"[2] His grandfather Murdoch Stewart, Duke of Albany was executed for treason in 1425 by King James I of Scotland.
He then served as governor of Stirling Castle and as an ambassador and diplomat, taking a leading role in the negotiations which led to the marriage of James and Margaret of Denmark in 1469.
When Albany and his English allies invaded Scotland, Lord Avandale was one of the faction who refused to fight and then proceeded to arrest the King.
Albany then proclaimed himself King Alexander IV of Scotland and immediately began to alienate the nobles—especially the powerful George Gordon, 2nd Earl of Huntly—by his harsh policies.
On Alexander's orders, Lord Avandale was then stripped of the Chancellorship because he had captured Albany's castle of Dumbarton for the King in 1479.