SIPTU will host a programme of cultural events to commemorate the 1916 Rising and the role that its headquarters Liberty Hall played in it.
The events will include a gala concert there tonight - featuring Christy Moore and Damien Dempsey - and talks on Easter Monday.
On Tuesday, President Higgins will lay a wreath at the James Connolly statue on Beresford Place in a state commemoration of those who lost their lives in the Irish Citizen Army and afterwards will unveil a plaque at the Hall.
Frank Connolly, Head of Communications with SIPTU, explains the role of the site in the rising:
Meanwhile, The President's rejected the idea that celebrating the centenary of the Easter Rising could cause unrest.
A series of State ceremonial events will get underway in Dublin from today to mark the 100th anniversary of the 1916 rising.
Over 3,700 members of the defence forces and emergency services will take part in this year's Easter Sunday centenary parade.
Michael D Higgins says today's ceremony at the Garden of Remembrance is an important moment for victims' families:
