The monumental work of Irish genealogy, the Leabhar na nGenealach was produced here in 1650 by Duḃaltaċ MacḞirḃisiġ (Dubhaltach MacFhirbhisigh).

The granting of collegiate status was confirmed on 8 September 1485 by a papal bull issued by Pope Innocent VIII (Super Dominicum Gregem).

The granting of collegiate status in 1484 required that the City of Galway and some surrounding parishes be severed from the Archdiocese of Tuam.

The warden, a position and title unique in Irish ecclesiastical history, was the spiritual leader of the city and was entitled to wear attire traditionally associated with a bishop (such as the mitre and crosier), while not having the power of ordination.

The warden and eight assisting vicars choral were elected every year in August by the mayor and members of the Corporation (city council) as then constituted.

[2] The Avowing Friendship service for a lesbian couple, it was reported, was conducted by the rector, the Reverend Patrick Towers, in September 2002.

[citation needed] The Reverend Patrick Towers was succeeded in July 2009 by Archdeacon Gary Hastings as Rector of St. Nicholas.