The MacLeans of Duart married into the family of the 1st Lord of the Isles in order to gain power and prestige, but not all of their political unions were to benefit the clan – in particular the case of Lachlan MacLean who married the daughter of the Earl of Argyll in the sixteenth century. The match was not a happy one and Lachlan took drastic action by stranding his wife on a rock and leaving her to drown. She was rescued by passing fishermen, and her kinsmen later avenged her by stabbing her husband to death.
The MacLeans were united with their Campbell in-laws in a mutual dislike of the MacDonald clan, one of the most powerful families in the Western Isles. In the sixteenth century, Lachlan Mor, chief of Duart, continually harried the MacDonalds of Islay and after his death in 1598, his sons took revenge on his suspected murderers, the MacDonalds, by carrying out a massacre of the people of Islay which lasted for three days.
The massacre of the MacDonald clansmen marked the point when the fortunes of the MacLean clan began to wane, and by the seventeenth century the Campbells had gained possession of Duart Castle and most of the MacLean estates. However, Duart castle was reclaimed by the family in 1911 and has now been restored as the family seat.