Peter Wallace was born on the 16th December 1871 in the townland of Granaghan Martin, Curraghroe, Co. Roscommon, the son of a small farmer, Edward Wallace, and his wife Catherine (née Leonard).
On the 16th May 1894 Peter Wallace was appointed to the R.I.C. at the age of 22 years. He is recorded as being 5'9" in height, a Catholic, with a previous employment as a postman. On the 19th December 1894, having completed training, Constable Peter Wallace, 56438, was allocated to Co. Wexford, where he remained until the 31st August 1907, when he was transferred to King's County (Offaly).
On the 28th July Constable Wallace married a shop assistant, Catherine Horan, in the Catholic Church at Cloghan, Co. Offaly. Following the marriage, and in accordance with R.I.C. regulations, Constable Wallace was transferred to Tipperary North Riding on the 10th September 1909.
On the 1st November 1914 Constable Wallace was promoted to the rank of Acting Sergeant, and on the 1st February 1918 he was promoted to the rank of Sergeant.
On Tuesday the 13th May 1919, while escorting a prisoner, Sean Hogan, on a train to Cork, Sergeant Peter Wallace, 56428, and Constable Michael Enright, 62005, were killed by a group of I.R.A. volunteers — Sean Treacy and Ned O'Brien, who were armed, James Scanlon and Sean Lynch, who were unarmed, and John O'Brien, who was armed with a .25 automatic revolver.
On the 14th May 1919 Sergeant Peter Wallace died at Kilmallock Union Hospital, Co. Limerick, of a gunshot wound to the abdomen inflicted on him at Knocklong Railway Station, Co. Limerick, during an attack on him and other members of the R.I.C. while escorting a prisoner to Cork prison. The death certificate states that he lived for 20 hours following the attack. At the time of his death Sergeant Wallace was the sergeant in charge of the R.I.C. Barracks at Roskeen, Ballycahill, Thurles, Co. Tipperary; he was two days short of 25 years' service.
