The National Library of Ireland website also allows for browsing by collection. Here are some of their relevant collections:
Éamon de Valera Photographic Collection
Eamon de Valera took part in the 1916 Easter Rising as well as the War of Independence, 1919-1921. He later served as Taoiseach for many years and became President of Ireland in 1959. This collection contains nearly 70 photographs spanning his political career.
Keogh Brothers Ltd., p. (1916). Irish Rebellion, May 1916: Ed. de Valera (Commandent of the Ringsend Area). Sentenced to Death; Sentence to Penal Servitude for Life. Dublin: Powell Press, 22 Parliament St.