Born 1887 in Dublin, and son of a papal count, George Noble Plunkett. Plunkett was educated by Jesuits at the Catholic University School, Belvedere College and Stonyhurst College in Lancashire, England. A gifted writer, he met Thomas MacDonagh when he had him as a tutor. MacDonagh was to become a close friend, as both were interested in poetry, religion and mysticism.
He graduated from UCD in 1909 but Plunkett contracted tuberculosis as a young man and spent periods in Italy, Algeria and Egypt in the years 1910-12. Plunkett edited the Irish Review, supported Arthur Griﬃth’s Sinn Féin and took the workers’ stand during the 1913 lock-out.
Along with MacDonagh and Edward Martyn, Plunkett also helped to establish an Irish national theatre. He was elected to the provisional committee of the Irish Volunteers in 1913 and later became a member of the IRB and fully committed to armed revolution. In April 1915 Plunkett went to Germany to assist Roger Casement in procuring arms and assistance.
With James Connolly and Séan Mac Diarmada, he was involved in the military strategy for the Rising and was the youngest signatory of the Proclamation. He and MacDiarmada are believed to have forged a document released on April 19, 1916, supposedly emanating from Dublin Castle, which suggested the authorities were about to suppress the Irish Volunteers. In poor health and recovering from an operation on his glands, Plunkett still joined other members of the Provisional Government in the GPO for the Rising.
He married Grace Giﬀord — a sister-in-law of Thomas MacDonagh — at Kilmainham on the night before he was executed. Just before he faced the firing squad, on May 4, he said: “I am very happy I am dying for the glory of God and the honour of Ireland.”