Mar, John Erskine, 2d (or 7th) earl of, 1558–1634, Scottish nobleman; son of the 1st (or 6th) earl. In 1578 he was persuaded by James Douglas, 4th earl of Morton, to assert his claims to Stirling Castle and the guardianship of the young James VI (later James I of England). Mar emerged in control of the king's person, while Morton attempted to recover his authority. After the rise of Esmé Stuart, duke of Lennox, and James Stuart, earl of Arran, Mar fell out of favor with the king. He participated in the capture of James in the raid of Ruthven (1582). After James's escape, Mar was received at court, but he was banished in 1584 and fled to England. In 1585 he joined the other banished Scottish nobles who invaded Scotland and overthrew Arran. Mar was made a member of the privy council. In 1601 he was sent as ambassador to England to offer secret assistance to the 2d earl of Essex in his rebellion. This was crushed before his arrival, and Mar spent his time negotiating the question of James's succession to the English throne. In 1603 he accompanied James to England and was made a member of the English privy council. From 1616 to 1630 he was lord high treasurer of Scotland.