Lennox, Matthew Stuart or Stewart, 4th earl of (lĕnˈəks) [key], 1516–71, Scottish nobleman. Related to the royal family, being next in the line of succession to the throne after James Hamilton, 2d earl of Arran, Lennox returned to Scotland in 1542, after service in France, to contest Arran's claim to be regent for the infant Mary Queen of Scots. In 1544 he allied himself with Henry VIII of England, marrying Margaret Douglas, the daughter of Henry's sister Margaret Tudor and Archibald Douglas, 6th earl of Angus. He lived in England for the next 20 years and led several invasions of Scotland. Lennox and his wife, a woman of great ambition and ability, were in great favor in England until the accession (1558) of Elizabeth I, who did not trust them. They became leaders among the Catholic nobility and succeeded in marrying (1565) their son, Lord Darnley, to Mary Queen of Scots. After Darnley's murder (1567), Lennox formally accused the earl of Bothwell of the deed but failed to appear at his farcical trial. When Mary was imprisoned, Lennox again became prominent and, through Elizabeth's intervention, was chosen regent to succeed (1570) the 1st earl of Murray. Mary's party, led by the Hamiltons and William Maitland, at once declared war against him. Lennox was stabbed to death in a raid during this war. His surviving son, Charles, was created earl of Lennox and was the father of Arabella Stuart.