[3] Having been made prebendary of Exeter, of Wells and of York, he was consecrated bishop of Hereford on 17 March 1370,[4] was translated to the see of London on 12 September 1375,[5] and became Archbishop of Canterbury on 30 July 1381, succeeding Simon of Sudbury in both these latter positions.
In 1373 he declared in convocation that he would not contribute to a subsidy until the evils from which the church suffered were removed; in 1375 he incurred the displeasure of the king by publishing a papal bull against the Florentines; and in 1377 his decided action during the quarrel between John of Gaunt and William of Wykeham ended in a temporary triumph for the bishop.
In 1377 the reformer appeared before Archbishop Sudbury and Courtenay, when an altercation between the duke and the bishop led to the dispersal of the court, and during the ensuing riot Lancaster probably owed his safety to the good offices of his foe.
In 1382 the archbishop's visitation led to disputes with the bishops of Exeter and Salisbury, and Courtenay was only partially able to enforce the payment of a special tax to meet his expenses on this occasion.
[3] He was responsible for the expansion of his family's chantry foundation in Somerset, Naish Priory, as well as significant building works at Christ Church Canterbury and Maidstone College.