Tom Clarke (1857-1916) was the key figure who linked the previous generation of revolutionary nationalists - the Fenians - with the new IRB activists. Clarke had emigrated to the US in 1880 in search of work, taking a position as an explosives operative for a construction company on Staten Island. In America he formed close ties with John Devoy, leader of Clan na nGael. He was sent to London in 1883 by the IRB to put his new skills to work for their cause. He was captured with a case of liquid explosives and spent just over fifteen years in Chatham and Portland prisons. On his release in 1898 he married Kathleen, a niece of one of his prison companions, John Daly (later Mayor of Limerick).

Clarke's newspaper and tobacco shop in Great Britain Street (Parnell Street) became a notorious centre for nationalist activity. The Secretary of the Post Office in Ireland giving evidence of precautions against disloyalty was to later say that "it seemed safe to classify as dangerous those who were credibly reported to be in more than occasional or chance communication with some one or some of the small group of persons known in Dublin to be dangerously seditious, e.g. T. J. Clarke."

As the oldest and most respected member of the Military Council that planned the Easter Rising of 1916, Clarke was given the honour of signing the proclamation first. He was shot in Kilmainham jail on May 3rd, in the first group of those to be executed with him were Pearse and MacDonagh.