[1][4] Achanduin Castle had long been thought to have been built by the Bishop of Argyll, though recent research has proved this to be unlikely.

[5] The remains of the castle are seated on the summit of a limestone ridge on the north-western shore of Lismore.

[2][4] Archaeological excavations show that Achanduin Castle was built about 1290, at a time when the Bishop of Argyll, Laurence de Ergadia, was himself possibly a MacDougall.

[2][4] The first documentary evidence of the castle appears in a grant of lands dated 1304 at Achichendone, when Eugenil de Ergadia, Lord of Lorn, of Menderaloch and of Lesmor granted to Andrew, Bishop of Argyll lands next to the castle.

[2][4] The MacDougalls were forfeit in 1308, and losing most of their lands following the Battle of the Pass of Brander and the loss of their stronghold of Dunstaffnage Castle.

[2][4] Around this time it is believed the MacDougalls left Lismore for the mainland to build Dunollie Castle.

[2][4] By 1452 The Bishop of Argyll seems to have had possession of Achanduin Castle and for a short time occupied it.