PRESIDENT Michael D Higgins and Finance Minister Michael Noonan will represent the State and the Government at the inauguration of Pope Francis in Rome today.
More than one million worshippers are expected to be in attendance at the Mass in the Vatican, along with delegations from 132 different governments.
Taoiseach Enda Kenny and Tanaiste Eamon Gilmore, who would normally attend such an event, will both be in the White House for the annual St Patrick's Day visit.
The most controversial head of state to attend will be Robert Mugabe, the Zimbabwean president, who is the subject of a travel ban by EU countries.
The United States will be represented by Joe Biden, the vice-president, who said president Barack Obama would have attended if he had not had a prior commitment to go to Israel.
The crowd of a million people set to attend the inaugural mass of Pope Francis will be make it the largest gathering of its kind since since the beatification of Pope John Paul II in 2011. That event drew 1.5 million to St Peter's Square and the surrounding streets.