This Border clan takes its name from the Barony of Johnston in Annandale where they appear to have been settled by the 13th century. They took a prominent part in Border warfare and had considerable power. They were loyal to the Crown and Sir James Johnston of Johnston was created Lord Johnston of Lochwood in 1633. 10 years later he was created Earl of Hartfell, his son was created Earl of Annandale in 1661. The Johnstons of Westerhall, Dumfriesshire, were an important family, of whom John, 2nd of Westerhall, was created a Baronet of Nova Scotia in 1700. The Johnstons of the north were another important branch.