A monastery was reputedly founded at Ardagh by St Mel (d.488), a kinsman of St Patrick. At the synod of Rathbreasail it was proposed that either Ardagh or Ardcarn should be one of the five diocese of Connaught. At the synod of Kells the diocese of Ardagh was assigned to Armagh; but from 1177 onwards there were complaints that it should be in the province of Tuam. A decision in favour of Armagh was given by Honorious III in 1216, and confirmed by Gregory IX in 1235. When bishop William O' Farrell died in 1516 the city is said to have consisted of four wooden houses. Hostile neighbours had so ruined the cathedral that mass had to be held out of doors. The fragments were unearthed during the 1970s, no other Romanesque remains are known at the site.
