Oswestry, in Shropshire, takes its name, according to an ancient legend, from a cross or "tree" erected on the spot where in 642 St. Oswald, the Christian king of the Northumbrians, fell in a battle with Penda, the heathen king of the Mercians.  The Welsh called the place Croes Oswallt, "Oswald's cross," and the English by the equivalent name Oswaldstre, and the town gathered round a monastery which was erected on the spot.  But the identification of Oswestry with Maserfeld, where the battle was fought, has not been established, and may have been merely a guess suggested by the name Oswaldstre.  There is no evidence that the Oswald of the cross was the same person as King Oswald. (Names and Their Histories, Taylor, 1896)