O'Cathasaigh is the Irish form of O'Casey. O'Casey was a friend of Thomas Ashe.
Thomas Ashe was a founding member of the Irish Volunteers. Sentenced to death after the Easter Rising this was commuted to penal servitude for life. Freed on 18 June 1917 by Lloyd George as part of a general amnesty, Ashe was re-arrested for sedition in August 1917. He died on 25 September 1917 at the Mater Hospital after being force-fed by prison authorities.