Archbishop Diarmuid Martin was born in Dublin on 8th April 1945. 

He attended schools in Dublin (Oblate School, Inchicore; De La Salle School, Ballyfermot; Marian College, Ballsbridge). He studied philosophy at University College Dublin and theology at the Dublin Diocesan Seminary (Holy Cross College, Clonliffe). 

He was ordained priest by Archbishop John Charles McQuaid in St Patrick’s Training College, Drumcondra, on 25th May 1969. He later pursued higher studies in moral theology at the Pontifical University of St Thomas Aquinas (Angelicum) in Rome. In 1973-74 he was Curate at the Parish of St Brigid in Cabinteely. In 1975 he was responsible for the pastoral care of Dublin pilgrims during the Holy Year in Rome.

He entered the service of the Holy See in 1976 in the Pontifical Council for the Family. In 1986 he was appointed Under-Secretary of the Pontifical Council for Justice and Peace, and in 1994 Secretary of the same Pontifical Council. On 5th December 1998 he was appointed Titular Bishop of Glendalough and received the episcopal ordination at the hands of Pope John Paul II in St Peter’s Basilica on 6th January 1999. 

During his service at the Pontifical Council for Justice and Peace, Archbishop Martin represented the Holy See at the major United Nations International Conferences on social questions held in the 1990’s. He also took part in activities of the World Bank and the International Monetary Fund, especially on the theme of international debt and poverty reduction. 

He spoke of the Church’s Social Teaching at conferences organised by the Bishops Conferences of the United States, of Australia, of Peru, of Scotland, and by the Council of Latin American Episcopates (CELAM), the Federation of Asian Bishops Conferences (FABC), and the Commission of the Episcopates of the European Union (COMECE).

He was a member of various Vatican Offices, including the Central Committee for the Great Jubilee of the Year 2000. In addition he was a member of the Joint Working Group for relations between the Roman Catholic Church and the World Council of Churches and a founding trustee of the World Faiths Development Dialogue (established by the Archbishop of Canterbury). 

In March 2001 he was elevated to the rank of Archbishop and undertook responsibilities as Permanent Observer of the Holy See in Geneva, at the United Nations Office and Specialised Agencies and at the World Trade Organisation. He led the delegations of the Holy See to the Ministerial Conference of the World Trade Organisation (Doha, 2001), the World Conference against Racism, Racial Discrimination, Xenophobia and Related Intolerance.

He was appointed Coadjutor Archbishop of Dublin on May 3rd 2003. The Liturgy of Welcome presenting him to the faithful of the diocese took place in St Mary’s Pro-Cathedral Dublin on 30th August 2003.