Seán Mac Diarmada (1883–1916) was one of the seven signatories of the 1916 Proclamation and a key organiser of the Irish Volunteers. He was executed by firing squad in Kilmainham Gaol on 12 May 1916.
Power’s 1940 bronze captures Mac Diarmada in a dramatically posed half-figure — one arm raised with open hand, the other drawn to the chest — expressing both declaration and conviction. The treatment is energetic and forceful, departing from the more restrained formal portrait bust that characterised much of Power’s earlier commemorative work.
The work is held in the collection of the National Gallery of Ireland. Power had strong personal convictions about how Mac Diarmada and the other 1916 leaders should be memorialised. When later commissioned for a public monument to Mac Diarmada in Kiltyclogher, Co. Leitrim, he insisted the figure face south rather than north — expressing his feelings about partition — and that it carry no chains, so that every aspect of the memorial would symbolise the freedom for which Mac Diarmada had died.