|Robert de Brus 5th Lord of Annandale
Other names for Robert were Robert Bruce Earl of Annandale and Robert de Bruce 5th Lord of Annandale.
Robert married Isabel de Clare, daughter of Sir Gilbert de Clare 7th Earl of Clare, Earl of Hertford and Gloucester and Isabel Marshal, on 12 May 1240. (Isabel de Clare was born on 2 Nov 1226 and died on 10 Jul 1264.)
1 Wikipedia.org, Robert de Brus, 5th Lord of Annandale.
Browning, Charles Henry, The Magna Charta Barons and their American Descendants (Philadelphia, 1898.), p. 137.