Eamon DeValera's life became dominated with Irish affairs. DeValera had now become an Irish Rebel. By 1915 he became a member of the IRB (Irish Republican Brotherhood). The handling of certain tasks within the IRB earned deValera a promotion to the rank of commandant. From here he became involved in the organising and planning of the Easter 1916 Rising. He was now second in command of the Dublin brigade, and was highly influenced by men like Thomas MacDonagh.

He was prepared, like the rest of the men, to give his life on the Easter morning of 1916. Throughout the week of fighting that began in 1916, it is often said that deValera’s operation at Boland’s Mill was the most successful campaign of the Rising. Even after the surrender of the men at the GPO in Dublin, led by Padraig Pearse, deValera was still prepared to fight on. He refused to believe that they had surrendered and it wasn’t until they notice that the firing of guns around the city of Dublin had stopped that he decided to surrender.

Death was a sure certainty for the men who led the Rising. DeValera was prepared for this and naturally accepted the fact that he was surely going before the firing squad. From jail he wrote a letter to his old rugby friend Jack Ryan. "I played my last match last week and lost". "Tomorrow I am to be shot so pray for me. It wasn’t until DeValera's devoted wife Sinead went to the American Consul General in Dublin to beg for her husband’s life on the grounds that he was an American citizen.

This fact is often argued amongst historians. Weather DeValera’s sentence was changed because of the fact that he was born in America or weather it was because public opinion had duly changed after the executions of the newly acclaimed heroes of the Rising is something that will be argued for many more years to come. The fact remains that after his involvement in the 1916 Rising Eamon DeValera had earned himself a reputation that was going to remain with him for the rest of his career.