Anstruther came of an ancient family with a strong electoral interest in Anstruther Easter Burghs and the county of Fife. Returned in 1715 for Fifeshire, which he continued to represent until 1741, he voted consistently with the Administration, adhering to Sunderland and Stanhope on the split in the Whig party in 1717, when he was rewarded with a place. Though originally attached to the Duke of Roxburghe, the head of the Squadrone, through whom he and his kinsman, Philip Anstruther, received a sum of £200 from Sunderland,
He died 27 Sept. 1753.
