Robert was the sole son of Walter Stewart, 6th High Steward of Scotland (d. 1326) and Marjorie Bruce, daughter of King Robert I of Scotland and his first wife Isabella of Mar. He was delivered by caesarean section. His mother survived his birth by some hours at most. As age and infirmity were telling upon him, the estates in 1389 appointed his second surviving son Robert, Earl of Fife, afterwards Duke of Albany, guardian of the kingdom. The king died at Dundonald in 1390, and was buried at Scone.