Peter White is a common enough name and there appear to be several men of that name who were active at the time.
IRA Captain Peter White, Company Commander in Ballyboughal/Swords, led the men who shot District Inspector Burke of the RIC in Balbriggan in September 1920. This action led in turn to the infamous ‘Sack of Balbriggan’ by the Black and Tans. However, this Peter White suffered fatal injuries on the 19th of April 1921 when he was hit in the side during an attack on the RIC at Connor’s Public House in Balbriggan County Dublin, he died on the 20th of April from his wounds, so he is not your man. During the attack RIC Sergeant Stephen Kirwan was also fatally wounded, Sergeant Kirwan died from his wounds on the 20th of April (BMH.WS1395 - James Crenegan). White was about 32 years old at the time of his death and was employed as a labourer.
There was also a red haired Peter White who was the Manager of Arthur Griffith’s paper the United Irishman and later the weekly Sinn Féin newspaper. This Peter White worked with Griffith in his offices on Fownes Street and was prominent in the Celtic Literary Society and used to contribute to a journal called the Seanachie. He was a member of the Provisional Committee of the Irish Volunteers and was one of the signatories of a letter dated 24/09/1914 which led to the split between the National and the Irish Volunteers. This Peter White was a cousin of the McLean family of Dublin and was related to Henry C Phibbs on his maternal side and a friend of Maude Gonne McBride (BMH.WS1765 - Séan T O’Kelly, BMH.WS0848 - Henry C Phibbs, & BMH.WS0283 - Maude Gonne McBride, (BMH.WS0384 - JJ (Sceilg) O’Kelly), he had a sister called Sara (BMH.WS0909 - Mrs. Sidney Czira). Liam de Roiste recalls a pleasant walk around Dublin with Peter White on 04/11/1905 “Reached Dublin about 12.30 p.m. Peter White met me at Kingsbridge. We walked around for awhile, visiting St. Patrick's Cathedral for historic interest; passing by the house where Lord Edward Fitzgerald was arrested and the Marshalsea, where Robert Emmet had his depot in 1803. Peter knows old Dublin well and seems to love it”. (BMH.WS1698 - Liam Roche (de Roiste)).
A third Peter White is mentioned several times in the Witness Statement of Stephen Keys (WS1209), particularly in relation to an abortive attack on a goods train which occurred during the Civil War, the Peter White mentioned in Keys Witness Statement is probably a different man to the red haired Peter White who worked with Griffith, but this needs to be confirmed. But given the fact that Keys was very active on the Republican side and any man working so closely with Griffith was likely to have been Free State they are probably different men.
If Dev and Oscar Traynor attended the funeral of your Peter White, I would guess that he is the man mentioned in Keys Witness Statement - which is a great read.
Hope that helps.
