Today marks the 100th anniversary of the formal handover of power by the British to the incoming Provisional Irish Government.
President Michael D Higgins, Taoiseach Micheál Martin and Tánaiste Leo Varadkar attended a ceremony to mark the centenary of the handover of Dublin Castle to the Irish.
President Higgins was greeted by a Defence Forces guard of honour as he arrived.
The event, which was held at the same time as the events of 100 years ago, was also attended by UK Ambassador in Ireland Paul Johnston.
Former Irish taoisigh Bertie Ahern and Enda Kenny attended today, as well as former presidents Mary McAleese and Mary Robinson. Sinn Féin leader Mary Lou McDonald also attended the ceremonial event.
In a short address shortly before the tricolour was hoisted in Dublin Castle, Mr Martin said: "As we honour the achievements of the revolutionary generation, we do so with pride that the State they helped to create is entering its second century of independent, democratic government."
President Higgins unveiled a plaque in Dublin Castle to mark the occasion.
In 1922, the handover took place barely a week after the Dáil voted to ratify the Anglo-Irish Treaty. It was a low-key procedure behind closed doors in Dublin Castle.
The popular image of the handover, as depicted in the film 'Michael Collins' - a formal ceremony in the Castle’s Upper Yard, troops from both armies on parade as the Union Jack is lowered and the Tricolour raised, Michael Collins in uniform - is fiction. No such ceremony ever happened.
The British had no interest in providing images for the world’s media of their withdrawal, and the Irish had too much to do to waste time and men on a formal ceremony.
Instead, what took place was far more mundane.
There was even uncertainty in the days immediately before the Handover, as to what, if anything, was planned at the Castle.
Members of the incoming Irish Provisional Government, led by its Chairman Michael Collins, left their base in the Mansion House early on the afternoon of Monday 16 January. Their schedule called for them to be back at the Mansion House for a full Cabinet meeting at 4pm.
They left for Dublin Castle in three taxis.
Crowds had gathered in anticipation of something happening. Barbed wire barricades were taken down by the British Army, the world's media filled the Lower Yard, alongside British Service personnel and the families of Castle officials.
The Irish party arrived ahead of schedule and went straight inside.
In the Privy Council Chamber, they were met by Lord FitzAlan, the Lord Lieutenant. He congratulated them, told them they were now duly installed as the Provisional Government, and the transfer of power would take place without delay.
A form of words was agreed to allow the new government begin work immediately, before the formal legal transfer of powers.
It was all over by 2.30pm. The new Irish Government Ministers returned to the Mansion House, for their scheduled Cabinet meeting. Which began exactly on time.
The Handover at Dublin Castle established two facts, that the British were on their way out of Ireland, and the Provisional Irish Government was now in power.
Additional reporting: Shane McElhatton, Laura Fletcher, PA