If the Kilmichael ambush, in which Tom Barry's flying column attacked a column of RIC Auxiliaries and killed 17 of them, had been the IRA’s most significant victory during the War of Independence, then the battle of Clonmult on 20 February 1921 must rank as its biggest defeat.

Even before Clonmult happened, it was evident the sheen of success was beginning to fade fast for the IRA.

Crown forces – the Army, RIC, Auxiliaries and Black and Tans – had begun to up their game. Their targeting of the IRA had become much more strategic.

The Restoration of Order Act allowed them powers of arrest and internment. Daily atrocities on both sides were met with increasing viciousness and the toll of killings, ambushes, raid and sabotage rose steadily in the winter of 1921.

The Crown forces had also upped the stakes in the crucial game of intelligence gathering and before Clonmult the strategy was already paying significant dividends.

On 28 January, they surprised an IRA unit planning an ambush in Dripsey, five men were executed afterwards.

On 15 February, a botched train ambush at Upton saw three IRA men killed. Six civilians were also killed and five wounded.

On the same day at Mourneabbey, four IRA men were killed or died of their wounds later. Another two were executed afterwards.

And in the townland of Clonmult, at an abandoned farmhouse on rising pasture land near Midleton in east Cork, the IRA would face its greatest losses.

The soldiers of the Hampshire Regiment who arrived at the farmhouse did so almost by accident.

Intelligence had led them to a nearby farm and, finding nothing, they approached the second. An immediate encounter with two IRA men out getting water from a well saw both killed.

As the military approached the farmhouse, by then headquarters and training base for the east Cork IRA Flying Column, a firefight ensued.

What happened next was contributed to in no small measure by inexperience, poor leadership decisions, carelessness and a fatal planning flaw by the IRA men, whose ages ranged from about 19 to about 30.

Some 20 of them had stayed too long, almost six weeks, in one place, increasing the risk of their presence being reported and their senior officers had left the farm to plan a train ambush for the next day.

Crucially, there were no sentries outside the house, as the column was preparing to leave it that evening. The least experienced were left in charge.

Now they were holed up in a building with only one means of entry and escape, the front door. No one had previously thought to ensure an alternative escape route. It was another major error of judgement.

After the initial firefight, the Hampshires, members of a regiment that had vast experience of the Western Front in World War I, quickly took their near perfect attacking positions around the house. The firing from both sides intensified.

At one stage during the battle there was a breakout from the house, three IRA men died and the acting man in charge escaped.

The soldiers then called for reinforcements and Auxiliary members of the RIC brought a powerful weapon - petrol.

Members of the Auxiliary police

The roof of the farmhouse was thatched and thus was presented the ideal method to flush out those inside the farmhouse and force their surrender.

As soon as thatch was set alight, what happened next was inevitable.

One man tried to burrow from the back of the house, to be met with shots. He was seriously wounded. While he was tended to by two others, the remainder walked out to surrender.

The captives were lined up against a cowshed and, almost immediately the shooting started.

In his book - "The Battle of Clonmult" - local historian Tom O’Neill says the men were shot by the members of the Auxiliary Division of the RIC.

One man was shot in the mouth, but the round failed to detonate. It was only when he was about to be killed that a British officer intervened to stop further slaughter, he says.

But how definitive is the account, based on the evidence? Dr Gabriel Doherty of UCC’s History Department said official explanations later suggested the men were escaping or otherwise killed during exchanges.

However, he said the explanation is implausible, given the number killed in one small area.

The battle began at about 4pm and ended within about two hours. Twelve men died outside the farmhouse and eight were captured. Of these, two were later executed.

The Clonmult disaster caused paranoia within the IRA in Cork about who had provided the intelligence that led to the raid.

However, it can be argued that by staying so long in one place; visiting pubs and a church and generally being seen about the countryside, the men may themselves have contributed in large measure to their discovery.

According to Gabriel Doherty, one man - a former soldier down on his luck - was abducted by the IRA as an informer. He was told if he confessed to providing the information that led the army to the farmhouse, he would be allowed emigrate to Australia.

If he didn’t, he would be killed. He confessed and was shot anyway.

So why did so many die after a surrender? Tom O’Neill said the actions of the Auxiliaries are most likely a response to the Kilmichael ambush less than two months earlier, in which so many of their colleagues were killed.

The flying column they discovered had also been involved in the killing of three policemen in nearby Midleton in the weeks leading up to the battle.

It could be added that the official powers and instructions given to the RIC Auxiliary Division meant there was little fear of their being held to any meaningful account.

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