The Lordship of Parliament of Erskine (Lord Erskine) was created around 1426 for Sir Robert Erskine. The sixth lord was created Earl of Mar in 1565, with which title (and the earldom of Kellie) the lordship then merged.
Another Lord Erskine was Thomas Erskine (d. 1832) (a younger son of Henry Erskine, 10th Earl of Buchan), who became Baron Erskine when he was appointed Lord Chancellor. This title was separate from that of the Earls of Buchan until 1960.