Mar, John Erskine, 6th (or 11th) earl of, 1675–1732, Scottish nobleman, leader of the Jacobites. He was nicknamed "Bobbing John," probably because of his political vacillation. He succeeded his father as earl in 1689 and in the following years was generally a member of the court party. He was twice secretary of state for Scotland under Queen Anne and played a leading part in promoting the union (1707) with England. After the accession (1714) of George I, he made an effusive offer of his services but was dismissed. He then withdrew secretly to Scotland, where he raised (1715) the standard for James Francis Edward Stuart, the Old Pretender, without orders from him to do so. The rebellion failed, largely through Mar's incompetence. He was defeated at Sheriffmuir and fled (1716) to France with the Pretender. He was attainted of treason in England, but his active dissatisfaction with the Jacobite court and his suspected treachery caused the Pretender also to break with him in 1724. Mar remained in exile until his death.