Bruce, Robert de IV d. before 1191, son of Robert III, was married in 1183 to Isabel, daughter of William the Lion, by a daughter of Robert Avenel, when he was given the manor of Haltwhistle in Tyndale as her dowry. He must have survived his father, if at all, only a short time, as his widow married Robert de Ros in 1191, and the date of his father's death being uncertain it may be doubted whether he succeeded to Annandale. He was succeeded by William de Bruce, his brother, in that fief, who was the only exception to the line of Roberts. William held Annandale along with the English manors of Hert and Haltwhistle till his death in 1215.
Sources:
Dugdale's Baronage, i. 449
Graham's Lochmaben, pp. 16 and 17.
Contributor: Æ. M. [Aeneas James George Mackay]
Published: 1886