Oswestry means "Oswald's Tree" (Welsh 'Croes Oswallt' meaning 'Oswald's Cross.') The town is named after the Christian King Oswald of Northumbria, who was killed there by the pagan King Penda of Mercia, at the battle of Maserfield in the year AD 642.
Reginald of Durham records that when King Oswald was killed, his right arm was taken up by a raven into a nearby ash tree, and thrown on the ground, where a well sprung up. You can visit 'Oswald's Well' at Oswald's Well Lane in Oswestry.
King Oswald had worked hard to spread the message of the Christian faith through the land. He co-laboured with the Irish bishop Aidan of Lindisfarne, sometimes translating for Aidan when he preached. Adian was a kind and generous man who travelled on foot ceaselessly through the countryside. Aidan invited everyone he met (both rich and poor) to embrace faith in Jesus Christ, or if they were already Christians, he encouraged them to devote themselves to good deeds and to caring for the poor.
The famous historian Bede, writing within a century of King Oswald's death, particularly notes that King Oswald was generous to the poor and to strangers.