 Not long after assuming the chiefship, Lachlan Og was forced to resign some of his lands to the chief of the Lamonts, because of the murder of Robert Lamont of Silvercrags by Lachlan Maclachlan of Dunnamuch. Lachlan Og led the clan in the Archibald Campbell, 7th Earl of Argyll's campaign against Sir James Macdonald of Islay and his rebellion in 1615.
