When Earl Duncan of Lennox was executed by James I , Macfarlane claimed the title and lands. This was rejected and the title was conferred on Sir John Stewart of Darnley which led to a long enmity between the contesting families. During the 16th century the clan found an outlet for their wartlike spirit in supporting the Earls of Lennox. Many of the clan, including the 13th Chief, fell against the English at the Battle of Pinkie in 1547, during the minority of Mary Queen of Scots. However the clan were to play a decisive part in her downfall as the Macfarlanes distinguished themselves at the Battle of Langside in 1568. During this time the Macfarlanes embarked upon a feud with the Colquhouns and in 1592 were responsible for the murder of Sir Humphrey Colquhoun and later a further feud developed with the Buchanans. These and many other acts of lawlessness committed by the Macfarlanes resulted in the clan being made landless and their name proscribed through an Act of Estates in 1642. The clan returned their loyalty to the crown in 1645 when Walter, the 16th chief, fought under Montrose for Charles I. Oliver Cromwell was to burn the MacFarlane seat at Inveruglas, Loch Lomond, in his invasion of Scotland.