The name is derived from a place name Lesslyn in Aberdeenshire. It is claimed that it was adopted by a descendant of Bartolf the Fleming, a nobleman who was in the retinue of Edgar the Aetheling when he came to Scotland in 1067 (after the Norman invasion in 1066). King Malcolm III made him governor of Edinburgh castle and granted him estates in Fife, Angus, the Mearns and Aberdeenshire. Bartolf's son was appointed constable of the royal castle at Inverury and his great-grandson obtained lands at Fythkill (later renamed Lesley) in Fife in 1282.
The Fife line clearly prospered and in 1445 George Lesley was appointed Lord Lesley of Leven and the title of Earl of Rothes in 1457. Later Leslies took up the career of professional soldier, fighting in Germany, France, Sweden and the Baltic.
During the religious upheavals of the Reformation, Norman Leslie was one of the chief participants in the murder of Cardinal Beaton in 1641. Alexander Leslie returned from the continent to take command of the Army of the Covenant. David Lesley, who had served King Gustav Adolph of Sweden, was a later Covenant commander but he was defeated by Cromwell at the Battle of Dunbar in 1650. After the restoration of the monarchy he was created Lord Newark.
The 7th Earl of Rothes became Lord Chancellor of Scotland was created a duke by Charles II in 1680.
The 9th Earl of Rothes was Vice Admiral of Scotland and governor of Stirling Castle. He supported the Hanoverians and commanded a regiment of cavalry against the Jacobites at the Battle of Sheriffmuir in 1715. Leslie House remained the seat of the Earls of Rothes until 1926.
The ruined castle of the Leslies in Aberdeenshire, together with the title of baron, were purchased in 1979 by David C Leslie, an architect from Aberdeen, who restored the building and ran it as a private hotel.
The use of the name as a forename (Leslie and Lesley) is of fairly recent origin.
The Leslie clan motto is "Grip fast".
Surnames regarded as septs (sub-branch) of the Leslie clan include Bartholomew and Lang.
