Ceremonies have been held to remember those who died in the 1916 Easter Rising.
Commemorations took place outside the GPO in Dublin, attended by Taoiseach Leo Varadkar and President Michael D Higgins - who laid a wreath.
Members of the Defence Forces, including the Army the Naval Service took part.
There was also a fly-past by the Air Corps.
The reading of the proclamation, laying of a wreath by @PresidentIRL and fly past by @IrishAirCorps https://t.co/OhXe1zFQl2 pic.twitter.com/84JvJxnJGy
— MerrionStreet.ie (@merrionstreet) April 1, 2018
It began with a reading of the Proclamation of Independence and the National Flag was lowered.
A minute silence was also held.
Separately, Heritage Minister Josepha Madigan laid a wreath at a ceremony in Glasnevin Cemetery to commemorate all of those who died.
Minister Madigan said: "It is a great honour for me to represent the Government at this ceremony of remembrance to commemorate all those who died in the cause of Irish freedom during Easter Week 1916.
"We remember in a special way those who rest in peace in this cemetery and the creators of our two great symbols of nationhood."
— âš–ï¸Josepha Madigan (@josephamadigan) April 1, 2018
Tributes were also paid to Peadar Kearney and Edward Hollywood.
Mr Hollywood brought the Tricolour to Ireland from France, with its message of reconciliation and friendship.
Mr Kearney wrote the original English lyrics of 'The Soldier's Song' in 1907.
The translation of his song - Amhrán na bhFiann - has been the Irish National Anthem since 1926.
