Isabella of Mar

Isabella of Mar (fl. c. 1277 – 12 December 1296) was the first wife of Robert Bruce VII, Earl of Carrick. Isabella died before her husband was crowned (as Robert I) King of Scotland. She and her husband were the grandparents of Robert II, King of Scotland, founder of the Royal House of Stuart.

Isabella was the daughter of Domhnall I, Earl of Mar (died 1297 - 1302) and Helen, widow of Máel Coluim II, Earl of Fife. It has been suggested that Isabella's mother was a daughter of Llywelyn ab Iorwerth. This is because Máel Coluim II had indeed "married a daughter of Llywelyn," but she was unnamed; Helen, mother of Isabella of Mar, became conflated with this unnamed daughter of Llywelyn ab Iorwerth because of the fact both were married to Máel Coluim II, Earl of Fife at some point. Genealogical insights indicate that the daughter of Llwyelyn the Earl of Fife married was actually Susanna, and that his widow Helen, who married Domhnall I after 1266, was an entirely different person.

Isabella's father was evidently an adherent of Robert Bruce V, Lord of Annandale (died 1295), a man who staked a claim to the Scottish throne. The close relationship between Domhnall's family and the Bruces is evidenced by two marriages; the first between Isabella and Robert, and the second between Domhnall's son and comital successor, Gartnait (died c.1302), and a sister of Robert Bruce VII.

The marriage of Robert Bruce VII and Isabella probably took place in the 1290s. The union produced a single child, a daughter named Marjorie (died 1316), who was born in about 1296. Robert and Isabella's daughter, Marjorie, married Walter Stewart, Steward of Scotland, and their son eventually reigned as Robert II, King of Scotland (died 1390).

Six years after Isabella's death in childbirth, Robert Bruce VII married his second wife, Elizabeth de Burgh (died 1327).