Clan Campbell
The Campbell of Possil's first major involvement was at the Battle of Inverlochy in 1645. During this period, Clan Campbell and Clan Lamont fought in various battles across Scotland. Following the battle, Clan Lamont used the opportunity to destroy much of the Clan Campbell's territory in the area. This resulted in a backlash from Clan Campbell, and the Scottish clan took both Castle Toward and Castle Ascog from Clan Lamont as a result. Clan Chief James Lamont surrendered, and Clan Campbell burned both castles to the ground. This period of conflict became known as the Dunoon Massacre.