Sean Connolly had been sent down from Longford by IRA headquarters to wake up the Roscommon brigade, and the site he chose at Scramoge was a small piece of tactical genius. The road bent sharply. A barn and farmhouse stood inches from the verge, easily loopholed for rifle fire. A hedge along the road could conceal a hand-dug trench. Connolly never saw his ambush. He was killed twelve days earlier at Selton Hill in neighbouring Leitrim, betrayed and shot in another column's debacle. Command passed to Patrick Madden, who pulled together the North and South Roscommon brigades, thirty-nine volunteers in all. Only fourteen would actually fire that morning. The rest were spread out blocking roads, holding the line of retreat open. Their armoury was a patchwork: thirteen rifles, including eleven Lee-Enfields and a single hunting rifle borrowed from somewhere; twenty shotguns, several barely serviceable; two or three Webley revolvers. Some of the guns had been quietly loaned over the county line from Longford. It was the largest single concentration of arms the Roscommon IRA had ever managed to assemble.

Morning crept by. The volunteers waited with the discipline that long waiting requires - aware that one mile away, several hundred trained British soldiers were quartered around the columns and gardens of Strokestown House. Just as a troop lorry finally rounded the corner from the direction of the town, an old man and a child came clattering up the road in a pony and trap, oblivious. The ambushers waved them frantically out of the way before the trap drifted into the killing zone. The lorry carried nine men - British Army regulars and Royal Irish Constabulary officers - and crucially it was unescorted, a breach of standard practice that the British inquiry would later question bitterly. Bolted to the lorry was a Hotchkiss machine gun, the kind of weapon that should have torn a hedge-line ambush to pieces. The first shots from the IRA came at point-blank range. The driver was killed instantly. The lorry lurched to a halt, and the men inside - several of them already hit - scrambled out behind the road wall.

The Hotchkiss gunner got off one burst before he was badly wounded and the gun fell silent. Captain Roger Grenville Peek, the patrol commander, was hit inside the lorry. He climbed out and ran for his life down the road toward Strokestown, four hundred yards before another shot brought him down. He was twenty-four years old. Lieutenant John Harold Anthony Tennant was killed in the same fight by a shotgun blast. With both officers dead, the surviving British troops - several of them wounded - surrendered. Four lay dead: Captain Peek, Lieutenant Tennant, an Army Service Corps driver, and Constable Edward Leslie. The IRA found two more men in civilian clothes in the lorry. They turned out to be Black and Tan constables under arrest by their own side - Buchanan and Evans. The volunteers took them prisoner along with the captured Hotchkiss gun, burned the lorry, and slipped away over the broad whale-back ridge of Slieve Bawn that rises just to the south.

The aftermath darkened almost immediately. The two captured Black and Tans offered to teach the IRA how to operate the Hotchkiss in exchange for their lives. Madden, Luke Duffy and Frank Simons made the decision the war had taught them to make: if released, the prisoners could identify volunteers who would then face execution if captured. Buchanan and Evans were taken to remote spots over the following two days and shot. From the British garrison at Roscommon, eight lorries and a Whippet tank rolled out at once. Three of the ambush volunteers were caught in the sweep - the Mullooly brothers Pat and Brian Nagle, captured trying to slip away, badly beaten on the road to Roscommon, and 'Cushy' Hughes, a veteran of the Irish Guards in the First World War, picked up while drawing his soldier's pension at a Roscommon post office. The next day, Michael Mullooly - Pat's brother, who had taken no part in the ambush - was shot dead in his own home by the RIC. Within weeks the truce would come, then the Treaty, then a civil war. The road still bends at Scramoge. The farmhouse is still there.