Alexander Bruce, Earl of Carrick

Alexander Bruce, Earl of Carrick was an illegitimate son of Edward Bruce, Earl of Carrick, younger brother of King Robert the Bruce, and Isabella, daughter of John of Strathbogie, 9th Earl of Atholl. According to The Brus they were married, but The Scots Peerage points out that this is unlikely because he did not immediately inherit his father's lands and titles; Freedom's Sword also says he was illegitimate.