The Cathedral Church of the Assumption of the Blessed Virgin Mary, Tuam, commonly called Tuam Cathedral, is the cathedral for the Roman Catholic Archdiocese of Tuam in Ireland. The geographic remit of the Archdiocese includes half of County Galway, half of County Mayo and part of County Roscommon. Prior to the English Reformation, the diocesan cathedral was St Mary's, which was constructed in the 14th century, on the site of an earlier building. Upon the appointment of William Mullaly by Queen Elizabeth I of England as Archbishop of Tuam for the Established church, the Roman Catholic clergy were dispossessed of the cathedral. Almost three centuries were to elapse before a relaxation of the Penal Laws permitted the building of a replacement – the current edifice.