"Chad then, being consecrated a bishop, began at once to devote himself to ecclesiastical truth and to chastity; to apply himself to the practice of humility, continence, and study; to travel about, not on horseback, but after the manner of the apostles, on foot, to preach the gospel in the towns, the open country, cottages, villages, and castles; for he was one of the disciples of Aidan, and endeavoured to instruct his hearers by the same actions and behaviour, according to his master's example and that of his own brother Cedd. Wilfrid also, who had already been made a bishop, coming into Britain, A.D. 666, in like manner by his doctrine brought into the English Church many rules of Catholic observance. Whence it came to pass that the Catholic institutions daily gained strength, and all the Scots that dwelt in England either conformed to these or returned into their own country."
This is Bede's account of the consecration of Wilfrid and Chad. At that time the diocese of York comprised the whole of Northumbria, including the south of Scotland. Under Oswald the see of Lindisfarne--the Iona of the Anglo-Saxons--was founded, containing within its jurisdiction the kingdom of Bernicia, until the establishment by Theodore of another see at Hexham. The writer of Wilfrid's life tells us that he objected to being consecrated by the English bishops, inasmuch as they were converts to the Scottish calculation regarding the celebration of Easter, or had received consecration from those who were of that opinion. Though Wini, who had been consecrated in Gaul, cannot be placed in either of these classes, yet Wilfrid knew he would summon to assist him two bishops who belonged to one of them; hence his preference for Gaul. Wilfrid's delay in Gaul, perhaps, excited the King's suspicions that he, like his friend Agilbert, was seeking a mitre there; or it may be that the king, influenced by the Scottish party (who could not forgive Wilfrid for the victory he gained over them at Whitby), consented to the election of Chad to the see.
Chad has been severely censured for accepting the bishopric under these circumstances. It may be, however, that he, stirred by sorrow at seeing the diocese left without a head, and doubting too, perhaps, whether Wilfrid would return, adopted this course, which may be condemned as uncanonical.