He was consecrated bishop of the Northumbrians during the hiatus between the death of the then Archbishop of Canterbury and the appointment of his successor. It seems that Chad’s consecration may have owed more to Celtic rites than to Latin ones. At any rate, the new Archbishop of Canterbury, Theodore of Tarsus, told Chad that his consecration was irregular. Chad graciously relinquished his authority, saying that he did not regard himself as worthy to be a bishop.
Struck by his humility, Theodore regularised his consecration and appointed him Bishop of the kingdom of Mercia, which had not long been Christianised. Chad established his See at Lichfield in 669 and remained there until his death of the plague in 672. Lichfield Cathedral is dedicated to St Chad and housed his bones until they were scattered in the 1540s during the vandalism of that time. His ‘day’ is 2nd March.