One half was retained by Walter Stewart, with the title of earl, and the other half was erected into a barony for William, the son of John the Red Comyn, and his wife, a daughter of the elder countess by her first husband. The component parts of the earldom which remained to Walter Stewart are not known. The death of King Alexander in 1286 threw the kingdom again into confusion, and during the rivalry which ensued between the parties of Bruce and Balliol, the Earl of Menteith supported the cause of Bruce. Walter was a party to the Turnberry Bond with his sons Alexander and John and the Bruces, which was signed at Turnberry Castle on 20 September 1286. In 1289 he was present at Birgham, and approved of the marriage proposed between Prince Edward of England and the young Margaret, Maid of Norway as she was called, the heiress of the Scottish Crown.