The title Earl of Leven was created in the Peerage of Scotland in 1641 for Alexander Leslie. He was succeeded by his grandson Alexander, who was in turn followed by his daughters Margaret and Catherine (who are usually not included in the numbering of the Earls). Thereafter, there was a dispute relating to succession to the title between David Melville and John Leslie, 1st Duke of Rothes. However, in 1681, Melville's claim was admitted after the Duke of Rothes died. In 1707, Melville succeeded to the title Earl of Melville, and thereafter the earldoms have been united.
The other titles held by the Earl are: Viscount Kirkaldie (created 1690), Lord Melville of Monymaill (1616), Lord Balgonie (1641), Lord Raith, Monymaill and Balewarie (1690). All are in the Peerage of Scotland.
His son David, 2nd earl of Melville (1660-1728), fled to Holland with his father in 1683; after serving in the army of the elector of Brandenburg he accompanied William of Orange to England in 1688.
Alexander Leslie, 1st earl of Leven, was succeeded in his earldom by his grandson Alexander, who died without sons in July 1664.
The younger Alexander's two daughters were then in turn countesses of Leven in their own right; and after the death of the second of these two ladies in 1676 a dispute arose over the succession to the earldom between John Leslie, earl (afterwards duke) of Rothes, and David Melville, 2nd earl of Melville, mentioned above.