Robert III, 1340?–1406, king of Scotland (1390–1406), eldest son and successor of Robert II. Known before his accession as John, earl of Carrick, he ruled for his father until 1389, when, having been crippled by a horse, he was supplanted by his brother Robert (see Stuart, Robert, 1st duke of Albany). The latter continued as virtual ruler after Robert III came to the throne. War with England during his reign was marked by Henry IV's invasion (1400) of Scotland and a retaliatory expedition into England, led by Archibald Douglas, 4th earl of Douglas, that met defeat at Homildon Hill (1402). The duke of Albany is thought to have been responsible for the death of the king's eldest son, David Stuart, duke of Rothesay, in 1402. Robert III died soon after his second son (later James I of Scotland) was seized and detained in England by Henry IV.