Thousands of people are expected to attend the annual Michael Collins oration at Béal na mBláth in Co Cork today.
Michael Collins was killed in a Republican ambush on August 22, 1922.
President Michael D Higgins will become the first sitting Head of State to deliver the oration this afternoon.
Chairman of the Béal na mBláth committee Dermot Collins has described it as an historic occasion.
"It has never happened before that a President in office delivers an oration at Béal na mBláth," he said.
"We're certainly looking forward to him and we're delighted and honoured that he has accepted our invitation.
"I hope today is good and I just might encourage people to travel in time - don't leave it late."
Elsewhere, Government Minister Leo Varadkar will give the oration at the annual Michael Collins and Arthur Griffith commemoration at Glasnevin Cemetery in Dublin at 12 noon.