The Catholic primate Archbishop Seán Brady has been elevated to the College of Cardinals by Pope Benedict XVI at a ceremony in St Peter's Basilica.
Archbishop Brady is the ninth new cardinal to receive the zucchetto - a skull cap - which was placed on his head by the Pope, and then a red biretta (a stiff square cap topped by three ridges - the so-called "red hat") over this. He will also then be told the title of the Roman church assigned to him, after which he will be formally greeted by his fellow cardinals.
Cardinal Seán Brady
Addressing the media after the ceremony, Cardinal Brady said he was "honoured and humbled".
He said priests and religious had a "unique and irreplaceable" role in society.
"These have been difficult, at times traumatic, years for the Church in Ireland. Yet in the midst of these challenges, the overwhelming majority of priests and religious have continued to serve their people, in humble patience, with quiet devotion and outstanding generosity," he said.
President Mary McAleese led the Irish contingent, accompanied by her husband Martin. Also present were Northern Ireland's Deputy First Minister, Martin McGuinness; the Secretary of State for Northern Ireland, Shaun Woodward; Minister for Foreign Affairs Dermot Ahern; and Government Secretary Dermot McCarthy.
A large Irish Catholic Church delegation included cardinals Cathal Daly and Desmond Connell, as well as the Archbishop of Dublin, Dr Diarmuid Martin; the Archbishop of Cashel, Dr Dermot Clifford; the Archbishop of Tuam, Dr Michael Neary; and 20 other bishops.
Mrs McAleese said Archbishop Brady's elevation to Cardinal was a "much deserved honour" for a pastoral man of "great humility, underpinned by great scholarship".
"That has to be a remarkable testament to the kind of faith-filled people the Irish are, to the kind of leaders that they have had in the Church, that at this time in our history, a very wonderful and grace-filled space in our history, we have the privilege of having three cardinals."
Taoiseach Bertie Ahern also paid tribute to Archbishop Sean Brady ahead of his appointment to the College of Cardinals.
The 68-year-old becomes the third cardinal on the island of Ireland when Pope Benedict XVI honours senior churchmen with the traditional red hat.
"Archbishop Sean Brady is fully deserving of the honour which Pope Benedict will bestow upon him," said Mr Ahern in advance of the ceremony.
"As Primate of All Ireland, he has exercised his pastoral care in a thoughtful, modest but always compassionate manner."
Mr Ahern paid tribute to Archbishop's particular leadership role in Northern Ireland and his tireless work on behalf of peace and reconciliation.
The Mass of the Rings will be held in St Peter's Square tomorrow where the new Cardinals will be conferred with rings by Pope Benedict and assigned a Church in Rome.
On Monday, Cardinal Brady will celebrate Mass in the Lateran Basilica, followed by a reception at the Pontifical Irish College.
His Eminence will then fly home on Thursday morning to Dublin airport where he will be greeted by the Taoiseach.
On his journey back to Armagh, he plans to visit St Peter's Church and Sienna Convent, Drogheda, Collon Monastery, Ardee, St Patrick's, Dundalk, Newtownhamilton, Keady and Ballymacnab.
The new Cardinal will arrive just outside Armagh at 7pm and board an open-top vehicle to parade through the town.
Mass will be celebrated in St Patrick's Cathedral, Armagh, at 8pm.
Cardinal Brady was ordained a priest in February 1964. He returned to Cavan to teach at St Patrick's in 1967.
In 1980, he was appointed vice rector of the Irish College in Rome - becoming rector in 1987 - and remained there until 1993, when he was appointed parish priest of Castletara, Ballyhaise, Co Cavan.
In February 1995, he was ordained Coadjutor Archbishop of Armagh and, a year and a half later on the retirement of Cardinal Daly, he became Archbishop of Armagh and Primate of All Ireland in October 1996.
On his creation as a cardinal, Pope Benedict XVI, assigned to Cardinal Brady the titular Church of St Cyricus and Julitta, named after martyrs.
Additional reporting: PA