William de Ker's grandson is said to have been allied to Sir William Wallace in the struggle for Scottish independence: "William Ker of Kersland joined Wallace in 1296. He and Stephen of Ireland are said to have been the only two of Wallace's men who survived the battle of Elcho. Ker was the constant friend and companion of Wallace. In 1305, when Wallace was taken prisoner at Robroyston, William Ker only was with him. They were found both asleep, and Ker was unfortunately killed in the scuffle".