Fianna Fáil members and supporters gather in Dublin today to celebrate the party's eightieth anniversary.
Taoiseach Bertie Ahern will host a special reception in the Mansion House where he will deliver a keynote address before invited guests.
Family representatives of former party leaders Charlie Haughey, Seán Lemass and party founder Eamon De Valera will be present.
Other special guests include former taoiseach Albert Reynolds, former president and minister Dr Paddy Hillery and current and previous Cabinet members.
Actor Barry McGovern will open proceedings with a performance of De Valera's address to the inaugural meeting of Fianna Fáil in Dublin's La Scala Theatre in May 1926.
A historical narrative on the achievements of the party will then be delivered by Minister for Children Brian Lenihan.
The guests will also view an archival exhibition: The Advance of a Nation - 80 Years of Fianna Fáil, which features photographs, election leaflets, historic posters and internal party letters.
"The Mansion House is a particularly appropriate venue, as the first Dáil convened in the Round Room in 1919 and the also played host to Fianna Fáil Árd-Fheiseanna for over 40 years," a party spokesman said.