The Battle of Maserfield is thought to have been fought here in 642 between Penda of Mercia and Oswald of Northumbria. Oswald was killed in this battle. According to legend, one of his arms was carried to an ash tree by a raven. Miracles were then attributed to the tree (as Oswald was considered a saint). The Welsh who held this area at the time called it "Croes-Oswellt" (meaning Oswald's cross). During the Anglo-Saxon period the town was called Oswald's Tree. Later this became Oswestry.