ARGYLL e ISOLE, DIOCESE of. - In Scotland, a suffragan diocese of S. Andrea (St. Andrews) and Edinburgh. Created around 1200 by separation from Dunkeld, it remained vacant in 1579 and was re-established on 4 March 1878. As for the see of the I., still united to that of A., founded, it is believed, around 447 by s. Patrizio, it remained united to the see of Man until the end of the 14th century. Vacant from 1553, it was re-established and united to the see of A. by Leone XIII on 4 March 1878. Statistics for 1948: population 12,000, almost all Catholics; 24 parishes and 34 diocesan priests. Present extent: the county of A., part of Inverness, and the islands of Bute, Arran, and the Hebrides.
The episcopal residence is at Oban, in Argylshire, where the pro-cathedral, dedicated to s. Colomba, is located.