 He was a Privy Councillor of King James IV and was created Earl of Cassilis by him in 1502.David Kennedy married Agnes Borthwick, daughter of William Borthwick, 3rd Lord Borthwick.Their son, Gilbert, 2nd Earl of Cassilis (29 Sep 1494 – 27 Aug 1527) married Isabella Campbell daughter of Archibald Campbell, 2nd Earl of Argyll.