William Wallace resigned as Guardian of Scotland after his defeat at the Battle of Falkirk. He was succeeded by Robert Bruce and John Comyn as joint Guardians, but they could not see past their personal differences. As a nephew and supporter of King John, and as someone with a serious claim to the Scottish throne, Comyn was Bruce's enemy. In 1299, William Lamberton, Bishop of St. Andrews, was appointed as a third, neutral Guardian to try to maintain order between Bruce and Comyn. The following year, Bruce finally resigned as joint Guardian and was replaced by Sir Gilbert de Umfraville, Earl of Angus. In May 1301, Umfraville, Comyn, and Lamberton also resigned as joint Guardians and were replaced by Sir John de Soules as sole Guardian. Soules was appointed largely because he was part of neither the Bruce nor the Comyn camps and was a patriot. He was an active Guardian and made renewed efforts to have King John returned to the Scottish throne.