The Bishop of Aberdeen (originally Bishop of Mortlach, in Latin Murthlacum) was the ecclesiastical head of the Diocese of Aberdeen, one of Scotland's 13 medieval bishoprics, whose first recorded bishop is an early 12th-century cleric named Nechtan. It appears that the episcopal seat had previously been at Mortlach (Mòrthlach), but was moved to Aberdeen during the reign of King David I of Scotland. The names of three bishops of Mortlach are known, the latter two of whom, "Donercius" and "Cormauch" (Cormac), by name only. The Bishop of Aberdeen broke communion with the Roman Catholic Church after the Scottish Reformation. Following the Glorious Revolution, the office was abolished in the Church of Scotland, but continued in the Scottish Episcopal Church. A Roman Catholic diocese was recreate