 Many of them, like Arthur Griffith, had little or nothing to do with the Rising.Camps such as Frongoch internment camp became "Universities of Revolution" where future leaders including Michael Collins, Terence McSwiney and J. J. O'Connell began to plan the coming struggle for independence.Sir Roger Casement was tried in London for high treason and hanged at Pentonville Prison on 3 August.