been more naturally employed as a guide in his own kingdom of Deira than in Lothian. The words of Florence of Worcester to which Skene refers in support of the Celtic version of the war do not seem materially to affect either theory; they might as well mean that Penda was marching northward against Bernicia as that he had actually entered the kingdom. Professor Rhys, in his 'Celtic Britain,' p. 133, endeavours to reconcile the Celtic story with the translation of 'Loidis' as the Leeds district, by placing the battle in Lothian, supposing that Oswy afterwards finished the war in the province of Deira, and suggesting that Penda fell there; but this is scarcely consonant either with the notices of the decisive character of the battle, or with the tradition apparently preserved in the words of Henry of Huntingdon, p. 60: 'percussus vero est per Oswium regem apud amnem Winwed.'
The Mercian army was overthrown with great slaughter, and the river being in flood the fugitives that were drowned in it were more than they that fell by the sword. Penda was slain, and with him fell nearly ill the thirty leaders of royal race, among them being Æthelhere, the cause of the war. Of the British leaders, Catgabail or Cadarail, king of Gwynedd, who deserted the host with his division, alone escaped. Oidilvald also deserted his allies, and waited the issue of the battle in a position of safety. Oswy fulfilled his vow by dedicating his daughter ÆIflæd, then scarcely a year old, to a monastic life, and by giving for the foundation of monasteries six estates in Bernicia and six in Deira, each of them being equal to the land of ten households or probably fourteen hundred and forty acres (Bæda, u.s. iii. 24; Robertson, Historical Essays, p. 98).
The result of this victory was that for a time the power of Mercia was completely broken, and that the country, together with the district of Lindsey and the land of the South-Angles, fell into the hands of Oswy. Of these territories he placed Mercia south of the Trent under his son-in-law Peada, as under-king, retaining the rest under his immediate dominion. His supremacy was acknowledged in the kingdom of the East-Angles and East-Saxons; he ruled probably directly over the Britons of Alclyde and the Scots of Dalriada, and is said to have brought the greater part of the Picts into subjection. He is the seventh of the English monarchs who, according to Bæda, held an imperial position, and who are described in the 'Anglo-Saxon Chronicle' as Bretwaldas. His victory enabled him to unite more closely the two Northumbrian provinces; Oidilvald lost Deira, and Oswy gave it in charge to his son Alchfrith. About a year later Peada died, and southern Mercia came under his immediate rule. But in 658 the Mercian ealdormen revolted, expelled the ealdormen that Oswy had set over their people, and made Penda's son Wulfhere their king. Oswy appears to have made no attempt to enforce his rule, and from that time his dominions were probably bounded on the south by the Humber. During the three years of his rule the Mercians accepted Christianity, and he is said to have joined Peada in founding the monastery of Medeshamstede, or Peterborough {Anglo-Saxon Chronicle Peterborough version, an. 665).
Oswy's marriage with Eanflæd brought the points of difference between the Roman and Celtic churches into prominence at the Northumbrian court; for the queen had been accompanied from Kent by a chaplain of the catholic observance named Ronan, and held to the Roman method of computing Easter, while Oswy kept the feast according to the Celtic usage in which he had been brought up; and so it might happen that he and his court would be celebrating Easter while his queen and her people were observing Palm Sunday. So long as Aidan, and after him Finan, held the bishopric of Lindisfarne, the differences between the two churches had not been held to be of much moment; but Colman (d. 676) [q. v.] was a man of another spirit, and under his teaching people began to regard these things as of vital importance. An abbot named Wilfrid or Wilfrith, to whom the queen had shown kindness, and who had lately returned to Northumbria after visiting Gaul and Rome, became the head of the Roman party in the north, and Oswy's son Alchfrith formed a close friendship with him, and joined him in advocating the catholic observance. Oswy must have inclined to the same side; for when the visit of the West-Saxon bishop to Alchfrith in 664 strengthened the Roman party, he submitted the questions at issue between the churches to the decision of a synod, and this was virtually to declare himself dissatisfied with the prevailing usage. At this synod, which was held at Whitby in the earlier half of the year, Oswy presided, being accompanied by Alchfrith, and declared himself convinced by the reasoning of Wilfrith. The assembly approved his decision, and so Northumbria deserted the Scottish church and accepted the Roman teaching [for this synod see under Colman]. During the absence of Wilfrith in Gaul, whither he was sent by Alchfrith that he might receive consecration, and on his return become the bishop of his kingdom or bishop of York, Oswy, finding that his return was delayed,
