It is not at all improbable that, as Geoffrey and the Welsh Bruts both refer to the battle in which Oswald fell as fought at or near Burne, the Oswestry traditions may have originally only had reference to the battle of Denis-BURN or Denis-brook, in which the Welsh Christian hero, Cadwalla, was slain by his hated rival, the Anglican Christian king Oswald, of Northumbria. It is utterly improbable that the Welsh Christians would dedicate a church to St. Oswald. The first Christian king of Northumbria, Edwin, the friend of Paulinus and Augustine, was slain by Cadwalla, "king of the Britons," or Brit-Welsh, in a battle at Heathfield (Hadfield, in the West Riding of Yorkshire), A.D. 633, in which he was aided by the pagan Penda. The Brit-Welsh Christians and the disciples of Augustine and Paulinus hated each other with more than ordinary sacerdotal intensity, and the former often entered into alliances with the pagan Anglo-Saxons, in order to avenge themselves on their detested rivals. One of the subjects of fierce contention between them, as is well known, related to the time for the celebration of Easter. Bede, referring to the defeat of Edwin at Heathfield and the consequences attendant thereon, says--
"A great slaughter was made in the church or nation of the Northumbrians; and the more so because one of the commanders by whom it was made was a pagan, and the other a barbarian more cruel than a pagan; for Penda, with all the nation of the Mercians, was an idolator and a stranger to the name of Christ; but Cadwalla, although he bore the name and professed himself a Christian, was so barbarous in his disposition and behaviour, that he neither spared the female sex, nor the innocent age of children, but with savage cruelty put them to tormenting deaths, ravaging all their country for a long time, and resolving to cut off all the race of the English within the borders of Britain. Nor did he pay any respect to the _Christian religion which had newly taken root among them_; it being to this day" (the 8th century) "the custom of Britons not to pay any respect to the faith and religion of the English, nor to correspond with them any more than with pagans."
Unquestionably no Christian church was dedicated to St. Oswald at Oswestry until after the final subjection of the district by the Anglican Christians. The probability therefore is that the locality was merely named, as in the other instances referred to, from the fact that it had become the location of a place of worship dedicated to him, and that gradually the various traditions about the saint and his rivals became inextricably confused. The last syllable "_tre_" is indicative of British influence in the formation of the word Oswestry, as in Pentre, Gladestry, Coventry (in Radnorshire), Tremadoc, Trewilan, Tredegar, etc., which simply means, according to Spurrell's Welsh dictionary, "resort, homestead, home, hamlet, town (used chiefly in composition)." Indeed, Oswestry is more suggestive of Oswy's-tre, and may refer to a successor who, some time after Oswald's death, built a church and dedicated it to the saintly monarch.