Complex sentence: The Maclaine of Lochbuie branch of the family are descended from Hector, the brother of Lachlan, who founded the Duart branch of the MacLeans.
Split into simpler sentences: The Maclaine of Lochbuie branch of the family are descended from Hector, the brother of Lachlan. Lachlan founded the Duart branch of the MacLeans.