"[4] Ryan became part of a group of former students lodging in St Enda's while they went to university who joined the Irish Republican Brotherhood.
One of the northern members the Dubliner Oscar Traynor, in his youth a professional footballer with Belfast Celtic F.C., later a war hero and later again a politician and Minister for Posts and Telegraphs.
At this stage, according to Ryan, Pearse was a constitutional nationalist who spoke for Home Rule from a platform shared with Tom Kettle and John Redmond, and refused to hear any criticism of the Irish Parliamentary Party.
He never makes a fight except when they assail his personal honour, when he bridles up at once... very delicate position... he is weak, hopelessly weak.He told Ryan that MacNeill was "a Grattan come to life again".
Ryan claimed that this document, presented to MacNeill on the Wednesday before the Rising and said to have been stolen from high-ranking British staff in Dublin Castle, was a forgery.
Ryan fought through the Easter Rising from 24 March 1916 in the GPO[6] under murderous artillery fire, and describes the battle vividly in his witness statement to the Bureau of Military History;[7] he describes the garrison retreating to Moore Street and quotes Pearse's sculptor brother Willie Pearse, who would be executed a few days later, as saying "Connolly has been asked out to negotiate.
He wrote books on Pearse, James Connolly, Éamon de Valera, Seán Treacy and John Devoy, and on Fenianism as well as writing on the Rising and the War of Independence.