The Archbishop of Armagh in the Church of Ireland is the Primate of All Ireland and the leader of that church, as well as being the diocesan bishop for the Diocese of Armagh and metropolitan of the Province of Armagh. Alan Harper is the present incumbent, having taken office on 2 February 2007.
The most learned of the primates was James Ussher (1625-56), whose most important works were "Veterum Epistolarum Hibernicarum Sylloge", published in 1632, and "Brittanicarum Ecclesiarum Antiquitates", which appeared in 1639. He left his valuable library, comprising several thousand printed books and manuscripts, to Trinity College, Dublin, and his complete works were published by that institution in twenty-four volumes. His judgment against toleration of Roman Catholics, i.e. "to consent that they may freely exercise their religion and profess their faith and doctrine is a grievous sin", was a signal for the renewal of persecution and led to the Rising of the Irish Catholics in 1641.
Lord John George Beresford (1822-62) was also distinguished by his munificence. He restored Armagh Cathedral and is said to have spent £280,000 in acts of public benevolence. On his successor, Marcus Gervais Beresford (1862-65), fell a large portion of the task of providing for the future organization and sustentation of the Church of Ireland, which was disestablished from 1 January 1871. Prior to the disestablishment of the Church of Ireland in 1871, the Church of Ireland Archbishop of Armagh was entitled to sit in the House of Lords as a Lord Spiritual, along with the other Archbishops in rotation.