It must have been some roar.
The crowd in the street outside knew the result before the TDs inside the building.
They heard the cheers inside the Council Chamber, the temporary Dáil, as the Ceann Comhairle Eoin MacNeill stood up to declare the result. Sixty-four in favour, 57 against.
How close was that?
This close.
Four TDs changing their minds would have been enough to declare the Treaty rejected.
Four votes the other way would have been enough to set the country hurtling into a new crisis, the course of which no one on either island, not the British government, not the Dáil government, not any of the most passionate speakers either side of the divide, not the IRA, not the British army, could predict.

The British media kept a close eye on the debate. This illustrated London News montage of photos from outside and inside the chamber, includes a very rare sight of the Republican Police, who provided security during the debates. Credit: Mary Evans Library
How had it come to this?
The wind had seemed to blow fair for the Treaty, backed from the very night of the signing by the press, international as well as domestic, the church, local authorities, and, if TDs' reports back from their constituencies after Christmas were accurate, most of the people, too.
And yet ... and yet ...
Dozens of TDs inside the chamber listened to all the arguments, remembered the pressure from their constituents, the press, the church - and still considered the Treaty terms too steep a fall from the ideals of the Republic.
This was no whim, no idle gesture. The final tally showed what forces and passions had come into play. It showed how nothing could be taken for granted.
Our last narrative ended on 8 December, with the Dáil cabinet irrevocably split on putting the Treaty before the Dáil: Collins, Griffith, Cosgrave, and Barton in favour. De Valera, Stack and Brugha against. Another tiny margin.
'The Treaty as it is drafted is not acceptable to us'
Two days later came a harbinger of the split that was to come.
Without recourse to headquarters, never mind to the cabinet, the officers of the IRA formation most responsible for prosecuting the War of Independence, the First Southern Division, met in Cork and afterwards issued an unequivocal statement:
"The Treaty as it is drafted is not acceptable to us ... we urge its rejection by the Government".
The credibility and influence of these men could not be ignored. This was a thunderclap of defiance.
Men with as much credibility would soon push back against those words during the debate, but the final breakdown of the Dáil vote a few weeks later would show that the men of the south were not outriders.
Perhaps because he saw how many of the best front-line fighters were against the Treaty already, Michael Collins knew that a majority for the Treaty at the cabinet table did not guarantee a similar majority in the Dáil.
Sinn Féin organiser and fundraiser Batt O'Connor recalled Collins calling unannounced to his home in the days before the debate, clearly agitated. Invited in, he began pacing the front room. Gesturing animatedly (his demeanour that night recalls descriptions of his behaviour in Hans Place the night of the signing, less than two weeks before), he said if the Treaty was rejected by the Dáil, he would go straight to Cork, to fight alongside his own people. His days of being 'chivvied and hunted' through Dublin were over.
Collins was haunted by the prospect of a return to war, as threatened by Lloyd George in the event of a rejection by the Dáil. Even if he suspected the British might not follow through, it was what they could do, more than what they would do, that he feared.
For all the talk during the debate about the significance for Irish independence of the imminent British withdrawal from the 26-county area, there was one awkward fact.
The British war machine in Ireland was intact. In fact, it was getting stronger.
With no fanfare, troops were still arriving after being redeployed from elsewhere in the empire, to take up positions around the country.
The military wireless network, that instantly linked every army unit across the island, was over budget and behind schedule, but it was finally complete that December.
The Royal Air Force, held back during the War of Independence for political reasons, was now cleared to fly ground-attack missions in the event of a return to war.
Collins and IRA Chief of Staff Richard Mulcahy knew that for all the cheering crowds swarming towns and cities after the Truce, the actual fighting was done by a few thousand men in a few places. Whole regions and classes had kept out of it. If war returned, those same few thousand men would answer the call, would stand and fight - and be slaughtered in open warfare.
Opponents assemble
The debate began on 14 December. TDs and ministers gathered for the opening sessions in the Council Chamber of University College Dublin, at Earlsfort Terrace.
The main protagonists lined up, Home Affairs Minister Austin Stack and Defence Minister Cathal Brugha sat to the left of the Ceann Comhairle, Eoin MacNeill. Minister for Foreign Affairs Arthur Griffith and Minister for Finance Michael Collins sat across the floor. The TDs faced the Ceann Comhairle, with the public behind them. Over a hundred journalists from all around the world sat behind MacNeill.

Too small, too crowded, terrible acoustics - the temporary Dáil premises in the Council Chamber in University College Dublin. Credit: Getty Images
The Council Chamber itself was not adequate to the task of hosting the debate.
Visitors to the same room today find it hard to believe it was the only option for such a decisive debate on the future of Ireland. It was too small, with the media and public all squashed in. Journalists complained that members of the public were not being stopped from occupying their reserved seats. The acoustics and sightlines were so poor, it was often hard to hear what was being said, or even see who was speaking.


Day and night, hundreds of onlookers waited outside the building for news of the debate. Credit: Getty Images

The crowds watched as TDs came and went from the debate. Credit: National Library of Ireland

TDs Constance Markievicz and Kathleen Lynn. Kathleen Lynn had been Chief Medical Officer of the Citizen Army. Credit: Getty Images
'This Treaty is simply an agreement ... it is not binding until the Dáil ratifies it'
Opening the debate on 14 December, President de Valera reminded those present just how pivotal these next weeks would be:
"It would be ridiculous to think that we could send five men to complete a treaty without the right of ratification by this assembly. That is the only thing that matters. Therefore it is agreed that this Treaty is simply an agreement and that it is not binding until the Dáil ratifies it."
The debate would focus on the implications of the offer of Dominion status for Ireland, the true significance of the proposed Oath of Allegiance, and the potential of de Valera's alternative proposals as a basis for seeking a return to the negotiating table.
What is striking now in reading the reports of the debates, is how the partition of the island got so little attention by comparison with those other issues. It was hardly raised, even by those most strongly opposed to the Treaty.
There were legitimate grounds for men and women on both sides of the debate to believe that this was one issue they could afford to set aside - for now. The fate of Northern Ireland was unfinished business for the future - that would be dealt with by the Boundary Commission.
British Prime Minister Lloyd George had offered the Boundary Commission as a way of agreeing the territory of the new entity in the northeast of the island – in a way that would render a separate Northern Ireland unviable. Lloyd George intended the Irish negotiators to see it like that, and they did. The horrified reaction of unionist leaders to the proposed commission only confirmed their belief.

Cabinet meetings were still being held back at the Mansion House during the debate, and crowds still turned up to follow proceedings. This photo is usually mistakenly captioned as being from Earlsfort Terrace. Credit: National Library of Ireland
TDs were briefed on the negotiations in London. Collins - ironically, considering the division that was to come - echoed the President's words when he stated that the delegates had not signed the final document as a treaty, but on the basis that each signatory would recommend it to the Dáil for acceptance.
'Those who speak lightly of war did not know a damn thing about it'
It had been agreed the first sessions would be held in private, to allow plain speaking, especially from the TDs who were also IRA officers. There was no sense in presenting the British with free and first-hand intelligence about the true state of play.
Seán Mac Eoin, North Longford IRA Commanding Officer, known as 'The Blacksmith of Ballinalee', was an early speaker. He wasted no time or words in the coming days. Others spoke on the same themes. Few spoke better.
He picked up on a remark by Cathal Brugha, that the Dáil was prepared for war, if it came. As a plain soldier, he felt it important to read into the record the facts.
He had one rifle for one man in 50 in his unit. For that one rifle, he had enough ammunition for 50 minutes' hard fighting.
"Those who speak lightly of war did not know a damn thing about it."

Longford IRA Commander Seán Mac Eoin: 'This Treaty brings the freedom that is necessary, it brings the freedom that we all were ready to die for'. Credit: Military Archives
Two days later, when Arthur Griffith proposed that the Dáil approve the Treaty, Mac Eoin seconded it, on the grounds that it brought everything he and his men had fought for. Symbols and shadows meant little to him, what meant more was that the Treaty terms would see the British army evacuated, an Irish force, properly equipped, in its place, and the nation free to develop in its own way.
"This Treaty brings the freedom that is necessary, it brings the freedom that we all were ready to die for."

Tipperary IRA officer Dan Breen: 'I would never have handled a gun or fired a shot... to obtain this Treaty'. Credit: National Library of Ireland
Mac Eoin's stand brought a personal rebuke in writing, from a fellow soldier. The senior Tipperary IRA officer Dan Breen told Mac Eoin in a letter: "I would never have handled a gun or fired a shot ... to obtain this Treaty".
Another IRA officer and TD Sean Hales used language that reflected a theme returned to again and again by the pro-Treaty side: He would only accept the Treaty as a jumping-off point, "the best rock to jump off" for the final achievement of freedom.
Collins and Griffith defended their action in signing the Treaty, on the basis of the credentials issued to them before the talks began, giving them authority to negotiate and conclude a settlement. Collins challenged de Valera's credibility in criticising the signing, when he had decided to leave the negotiations to them, and to remain in Dublin.
Griffith claimed that neither side had bound their hands by signing the Treaty, both had to answer to their respective parliaments.
"We went to see how to reconcile the two positions, and I hold we have done it."
De Valera pressed back on the issue of the powers of the delegates. In particular, he returned to the exchanges during the chaotic cabinet meeting of 3 December in Dublin, at which, de Valera reminded Griffith, he had undertaken not to sign without referring back to Dublin.
Worse, he said, not only was the Treaty signed, but the text was published in the world's press, and its merits were being extolled before the cabinet in Dublin had even seen it.
A roadmap to an honourable settlement, or a document full of traps?
A theme Collins and Griffith returned to several times was that what had been offered by de Valera as an alternative to the Treaty, in what became known as Document Number Two, did not mention a Republic, and differed so little from the actual Treaty, as not being worth fighting for.
De Valera's Document Number Two proposed that there would be no Oath of Allegiance, that Ireland would have an "External Association" with the British Commonwealth. In areas of 'common concern' - concerted action would take place on issues like defence, peace and war, and political treaties.
Ireland would recognise that His Britannic Majesty was head of the Commonwealth, but he would not be head of the new Irish State.
It proposed some changes to the defence provisions, but left the Treaty's partition clauses untouched, apart from a clause stating that there would be no recognition of the right of any part of the (32-county) country to be excluded from the authority of the National Parliament.
De Valera admitted there was very little difference to the Treaty in what he proposed – except in one major way: That his proposal meant that an independent Ireland would be outside of, separate from, but would freely associate in an honourable manner with another group (ie: the Commonwealth).
Collins found it hard to conceal his contempt for the argument offered. He believed that no delegation returning to London with such proposals would even get a meeting with the British government.
He privately believed that Document Number Two was full of traps for any Irish government to fall into, were it to be accepted. The wording was so vague, the British could put any interpretation they wanted on it, to justify interfering in Irish affairs. Moreover, if External Association were to mean anything, it would mean Ireland would be out on its own, without the support of the Dominions like Canada, Australia and South Africa, in any showdown with the British.
De Valera withdrew Document Number two from discussion, at the end of the private session on 18 December.
Collins and de Valera face to face

Éamon de Valera: '....it is absolutely inconsistent with our position; it gives away Irish independence; it brings us into the British Empire...' Credit: Getty Images

Michael Collins: '...it gives us freedom, not the ultimate freedom that all nations desire and develop to, but the freedom to achieve it'. Credit: Getty Images
But he stuck to his argument that the Treaty had been signed under duress. It had given away the possibility of an independent Ireland, the oath had acknowledged the King of England as the source of executive authority in Ireland. The Free State would be a creature of the crown, as it would be set up by a law enacted by the UK parliament, in the name of the crown.
"I am once more asking you to reject the Treaty for two main reasons, that ... it is absolutely inconsistent with our position; it gives away Irish independence; it brings us into the British Empire; it acknowledges the head of the British Empire, not merely as the head of an association, but as the direct monarch of Ireland, as the source of executive authority in Ireland."
This was Collins' response:
"I do not recommend it for more than it is. Equally I do not recommend it for less than it is. In my opinion it gives us freedom, not the ultimate freedom that all nations desire and develop to, but the freedom to achieve it."
"Rightly or wrongly when you make a bargain you cannot alter it, you cannot go back and get sorry for it and say 'I ought to have made a better bargain'. Business cannot be done on those bases. I must make reference to the signing of the Treaty. This Treaty was not signed under personal intimidation. If personal intimidation had been attempted no member of the delegation would have signed it."
"At a fateful moment I was called upon to make a decision, and if I were called upon at the present moment for a decision on the same question my decision would be the same. Let there be no mistake and no misunderstanding about that."
"I say that rejection of the Treaty is a declaration of War".
Collins' words here give an important insight into his strategic thinking.
He understood how a rejection of the Treaty by the Dáil would be portrayed by the British government to the world.
Global public opinion had been a key ally of the Republican cause during the war. The British had calculated that an offer of Dominion status to the Irish would be considered by most observers to be a fair offer. Rejection would put the British on the front foot, and, if it came to it, would provide cover for a return to war, for which the Irish would be blamed.
The Treaty on the verge of rejection?

'The Treaty will almost certainly be beaten'. A pensive Michael Collins leaving the building during a break in proceedings. Credit: Getty Images
Collins' words in that exchange have echoed through history, but at the time he didn't think they would make much difference. He described it later to his future fiancée Kitty Kiernan as "the worst day I ever spent in my life ... the Treaty will almost certainly be beaten".
Dublin Castle official Mark Sturgis' diaries show that his sources were picking up exactly the same fear.
One told him that as things stood on 20 December, in the final tally they would be defeated by two votes.
Sturgis was also hearing from London of Lloyd George's mounting alarm at the way the debate was going. He was starting to realise that the signing of the Treaty, into which he had put so much effort, had not settled the issue.
But for all the words spoken in the Dáil debates, there were other words being said elsewhere off the record by the same people, that sent a very different message.
The pro-Treaty side knew that a few quiet words spoken far away from the debate chamber could have as much effect on the final tally as words spoken inside, on the record.
Collins and other pro-Treaty figures were saying different things to different people, telling them what they wanted to hear.
Northern IRA officer Frank Aiken recalled later that at a dance in Clones, Co Monaghan, the local senior IRA officer Eoin O'Duffy solemnly assured those comrades near him who would listen, like Joe McKelvey and Seán Mac Eoin, that the signing of the Treaty was just another tactical move, to win time to re-arm the IRA.
Collins himself told Sean Hales that, just as the English broke the Treaty of Limerick, so the IRA would break this Treaty, once it had re-armed and strengthened.
It didn't matter how much of this was actually meant, what mattered was its intended effect on the thinking of those who would have to vote at the end of the debate.
Central to the Treaty provisions was the offer to the new State of Dominion status, inside the empire, with independence on a par with that enjoyed by Canada or Australia.
Collins argued that shared status with such countries meant they would have a vested interest in Ireland winning real freedom. They would in effect be guarantors of Irish freedom.
The anti-Treaty speakers were almost mocking in their rejection of this notion. The Irish side in the Treaty negotiations had argued that the Canada/Australia model would not work, simply because Ireland was physically too close to Britain, and any authority granted to the crown over Ireland would be far more intrusive than in the distant Dominions.

Austin Stack: poured scorn on the idea that Ireland could be a Dominion like Canada or Australia. Credit: Getty Images
In the Treaty debate, Minister Austin Stack enjoyed pouring scorn on the idea that Irish people wanted to be Canadians, but his words got to the heart of the anti-Treaty rejection of the Dominions as a model for Ireland.
Of course Canadians and Australians would swear an Oath of Allegiance to the crown, were they not of English stock, children of England? The Irish were never children of England. Their relationship with England was through invasion and resistance.
A fateful interlude: The Treaty Christmas
Christmas was imminent, and thoughts in the chamber turned to a recess.
With so many of the public backing the Treaty, the anti-Treaty side feared the effect on wavering TDs, of exposure to their own constituents. Seán MacEntee wanted to stay in session through the Christmas period. De Valera was against going into recess.
But the Dáil did go into recess for Christmas.
The fears of the anti-Treaty side were realised. There may have been an agreement to de Valera's proposal that no member of the house engage in any public campaigning over the holiday period, but that didn't stop the main newspapers - the Irish Independent, the Irish Times, the Freeman's Journal – pushing the pro-Treaty case, nor the Catholic hierarchy calling on all TDs to heed their constituents.
When the Dáil re-assembled on 3 January, a handful of TDs told the debate that they had decided to change positions and support the Treaty, convinced by conversations with their constituents during the recess.
On the first day back, JJ Walsh (Cork Borough) said he believed nine out of ten people in his constituency in Cork were for the Treaty.
On the day of the vote, Daniel O'Rourke (Mayo South-Roscommon South) said had the vote happened before Christmas, he'd have voted against. The people he trusted the most down home, he said, told him there was no alternative to accepting the Treaty.
PJ Ward (Donegal) said he had consulted almost all the Sinn Féin clubs in the constituency over Christmas, and 17 out of the 20 clubs he visited asked that the Treaty be ratified 'under protest'.
One look at the final margin of victory for the Treaty backers will be enough to see how crucial that handful of votes would turn out to be.
Into the last days: bitter words
On the day before the vote, 6 January, de Valera announced his intention to resign as President of the Republic - then to stand again for re-election. He was explicit in declaring his intention to clear out the existing cabinet and appoint one united behind his opposition to the Treaty, and his Document Number Two.
Collins was having none of it. He insisted that no resignation by the President could take place before the vote was taken.

Ceann Comhairle Eoin MacNeill arriving on the day of the vote on ratification. He would have the casting vote, in the event of a tie. Credit: Getty Images
The vote was taken on 7 January. A roll call showed 122 deputies in the chamber.
The main final speakers were Arthur Griffith on the pro-Treaty side, and Cathal Brugha on the anti-Treaty side.

Defence Minister Cathal Brugha. His bitter and personal attack on Michael Collins just before the vote, backfired.
Cathal Brugha spoke. In retrospect, given the bitterness of his words, the anti-Treaty side might have preferred to put up someone else, so close to the actual vote. Even as he spoke, deputies on both sides could sense the damage he was doing to his own cause.
The main thrust of his speech was a direct attack on Michael Collins. His theme was, since so many seemed likely to vote for the Treaty because of Collins' role during the War of Independence, what was that role, and how much of his reputation was deserved? How many fights was he in - "can it be authoritatively stated that he ever fired a shot at any enemy of Ireland?"
What he hoped to achieve with this attack is unclear. Was not the chamber full of men on both sides of the debate who had fired many shots at enemies of Ireland, and women who had supported them, none of whom based their esteem for Collins on his prowess as a frontline soldier?

Arthur Griffith: 'The principle I have stood on all my life is the principle of Ireland for the Irish people ... I will not sacrifice my country for a form of government'. Credit: Getty Images
When Griffith spoke, he returned to his theme of practical de facto independence being offered by the Treaty:
"The principle I have stood on all my life is the principle of Ireland for the Irish people. If I can get that with a republic, I will have a republic. If I can get that with a monarchy, I will have a monarchy. I will not sacrifice my country for a form of government".
The Vote
The vote was called. Collins had the last words, before the business began:
"Let the Irish nation judge us now and for future years."
Ceann Comhairle Eoin MacNeill ruled that each TD would have one vote, even if they had been elected in two constituencies.
He himself would cast the deciding vote, in the event of a tie.
There was no secret ballot, no lobby to pass through. Each deputy stood up and called out his vote, in Irish:
"Is Toil" (I wish it)
"Ní Toil" (I do not wish it).
The open call must explain how the result of the vote was known by the crowd outside, perhaps passed out by a quick-counting observer before Eoin MacNeill could call it.

Eoin MacNeill, Ceann Comhairle : 'The result of the poll is sixty-four for approval and fifty-seven against. That is a majority of seven in favour of approval of the Treaty'. Credit: National Library of Ireland
It was a long way from the chamber, but the roars and cheers from the steps were heard in the room as he stood to give the final tally.
"The result of the poll is 64 for approval and 57 against. That is a majority of seven in favour of approval of the Treaty."
As the implications of the decision sank in around the chamber, so did the closeness of the margin. Just four more TDs voting against would have swung it.
There would be time later to analyse the vote. Events moved swiftly in the chamber. De Valera stood up immediately.
From the official record:
"President de Valera: 'It will, of course, be my duty to resign my office as Chief Executive. I do not know that I should do it just now'.
Mr M Collins: 'No'."

Mary MacSwiney: 'Make no doubt about it. This is a betrayal, a gross betrayal; and the fact is that it is only a small majority, and that majority is not united'. Credit: National Library of Ireland
Collins called for unity. Mary MacSwiney TD, sister of Terence MacSwiney, had an answer for him:
"Make no doubt about it. This is a betrayal, a gross betrayal; and the fact is that it is only a small majority, and that majority is not united; half of them look for a gun and the other half are looking for the fleshpots of the empire. I tell you here, there can be no union between the representatives of the Irish Republic and the so-called Free State."
De Valera called on all those deputies who had voted against the Treaty to meet him next day, wherever premises could be found.

President de Valera: He wanted the last word after the vote, but was overwhelmed by the gravity of the moment. Credit: Getty Images
He asked for the last word. Even in the dry language of the official Dáil record of what he said next, his emotion was unmistakable.
From the official record:
"'I would like my last word here to be this: we have had a glorious record for four years; it has been four years of magnificent discipline in our nation. The world is looking at us now - '
(The President here breaks down)."
The house adjourned at 8.50pm. It was decided there would be no meetings until the Monday.

An exhausted Michael Collins photographed at the Gresham Hotel, the night of the vote to ratify the Treaty. Unusually for Collins, he is happy to be photographed at an unguarded moment. Credit: National Library of Ireland
De Valera resigns
If proponents of the Treaty thought that the vote on the Saturday was the final word, events in the chamber on Monday the 9th showed how close events were to tipping over into chaos.
Éamon de Valera resigned as Chief Executive. Collins tried to prop up the tottering edifice of unity by proposing a committee of public safety. De Valera pressed on, insisting that there be a vote on re-electing him, knowing there would be TDs who had voted for the Treaty, but who did not consider that a vote against him.
A vote to re-elect him would allow him do what he had wanted to do before the vote on the Treaty - clear out the current cabinet and appoint one united behind him.
Pro-Treaty TDs and ministers claimed that this would have allowed him repudiate the vote on the Treaty.
The result of that vote was even closer than the vote on the Treaty. The proposal to re-elect de Valera was lost 58 to 60. Mary MacSwiney's depiction of the Treaty majority as 'not united' was spot on.
Two TDs who voted for the Treaty 'crossed the floor' and voted for de Valera: Robert Barton and Paul Galligan.
Two more pro-Treaty TDs abstained, Tom O'Donnell and Liam de Róiste.
De Valera himself abstained.
The implications of a vote to re-elect de Valera would have been enormous; the cabinet behind de Valera, the Dáil behind the Treaty, Collins and Griffith having to set up a provisional government. There would in effect have been two governments. Each with an army at its back.
Could anarchy have been far behind?
The Dáil met the next day, 10 January, to elect a new President. There were exchanges between Griffith and de Valera about just what the new President would be President of - the Republic or of the Dáil. Griffith showed his customary impatience with titles.
De Valera's position hardened as the morning went on. Then, before the vote, he stood up and declared he would leave the chamber "as a protest at the election as President of the Irish Republic, of the Chairman of the Delegation (to London), who is bound by the Treaty conditions to set up a state which is to subvert the Republic".
He called on his supporters to follow him out of the chamber.


WALKOUT: Photographs of Éamon de Valera and the anti-Treaty TDs, taken just after they walked out of the Dáil in protest. Credit: Military Archives
'Deserters all!' 'Oath breakers and cowards!'
The Dáil minutes record what happened next.
The charitable explanation is that the tension, exhaustion, and frustration finally told on everyone in the room.
From the official record:
"MR. M. COLLINS:
'Deserters all! We will now call on the Irish people to rally to us. Deserters all!'
MR. CEANNT:
'Up the Republic!'
MR. M. COLLINS:
'Deserters all to the Irish nation in her hour of trial. We will stand by her'.
MADAME MARKIEVICZ:
'Oath breakers and cowards'.
MR. M. COLLINS:
'Foreigners - Americans - English'.
MADAME MARKIEVICZ:
'Lloyd Georgeites'."
The minutes do not record the atmosphere in the chamber after such an exchange of poisonous insults, but even as the last of de Valera's supporters was filing out, the motion to elect Arthur Griffith as President of Dáil Éireann was being put to those remaining by the Ceann Comhairle.
He was unanimously elected by 61 votes. He immediately appointed a new cabinet.
FINANCE: Michael Collins
FOREIGN AFFAIRS: G Gavan Duffy
HOME AFFAIRS: Eamonn Duggan
LOCAL GOVERNMENT: Alderman W T Cosgrave
ECONOMIC AFFAIRS: Kevin O'Higgins
DEFENCE: Richard Mulcahy
Why was the margin of victory so narrow?
Consider the momentum behind the Treaty, from the moment of its publication:
Worldwide acclaim from press and governments, most of the national press supporting it.
The GAA's President Dan McCarthy was a strong supporter.
Collins had worked his connections in the Irish Republican Brotherhood, to keep them on board, and in turn they worked on IRA officers to back the Treaty.
The Catholic Church backed it.
Public opinion was mostly in favour of ratification.
The Christmas break, which took the momentum out of the debate, ensured TDs were exposed to their constituents' strong support for ratification.
Over 300 public bodies declared their support for the Treaty before the vote.
And yet ... all that momentum never turned into comfortable majorities, on either the Treaty vote, or on de Valera's future as President of the Republic.
How the vote broke down
Historians have pored over how the vote broke down.
The way the IRA officers who were also TDs voted gave a good indication of how the organisation would fracture in the months ahead.
About three-quarters of all officers at Brigade level voted against (Remember the Brigade officers of the Cork 1st Division broke ranks almost immediately after the signing). Divisional-level officers voted 11-8 against. General Headquarters officers voted over two-to-one in favour.
1916 veterans were narrowly (one vote) against.
Schoolteachers and local government staff were almost equally split.
One surprising conclusion from the debates was that partition did not figure nearly as much as might be expected. Almost no TDs, even those from the six counties or (what would become) the border region, cited partition as a reason for voting against the Treaty.
The prospect of the Boundary Commission on the future territory of the new entity of Northern Ireland had led Griffith and Collins to sign the Treaty. It had also re-assured most TDs that partition would be temporary.
And this despite the fact that, almost in parallel with the Dáil debates, Lloyd George in the House of Commons debate on the Treaty was defending the Boundary Commission provision against charges it gave too much away. His principal argument? That the way it was worded in the Treaty gave the commission very little leeway in terms of transfer of territory.
The new reality out on the streets
On the same afternoon that Griffith was announcing the new cabinet, new realities were already taking shape on the streets outside.


British troops in work fatigues dismantle the barriers and bunkers around Dublin Castle. Credit: Cashman Collection
At Dublin Castle, guarded, padlocked, sandbagged and barricaded for over two years, British soldiers suddenly emerged onto the street outside, not in combat uniforms but in white work clothes. They began to dismantle the barbed-wire entanglements at the castle approaches. Curious passers-by who stopped to watch then looked up and saw that the heavy gates stood wide open.
In less than a week, members of the Provisional Government would be driven through those gates. The Lord Lieutenant would transfer power to Michael Collins.
The new government would take control of the Free State.

An early appearance in the Mansion House for the new cabinet, in the days after the vote to ratify the Treaty. Arthur Griffith and Liam Cosgrave are seated on the left of centre, and Michael Collins and Richard Mulcahy face the speaker. Credit: Alamy
If the members of the new government thought the Treaty debate had settled matters, one look at the tiny margin of victory would have told them: This business is not settled.
Six months later the fledgling State would be fighting for its very existence.
TO BE CONTINUED.