In AD 731, Tatwin was promoted to the See of Canterbury, through the influence of King Aethelbald of Mercia, and was consecrated on 10th June. Bede concluded his Ecclesiastical History in the same year. Of Tatwin, he says that he was vir religione et Prudentia insignis, sacris quoque literis nobiliter instructus (a man notable for his prudence, devotion and learning). This is clearing shown in the two surviving manuscripts of his Riddles and four of his Grammar. The former deal with such diverse topics as philosophy & charity, the five senses & the alphabet and a book & a pen.

His short archiepiscopate of three years seems to have been uneventful. Though he is known to have consecrated Bishops of Lindsey and of Selsey in AD 733. He died on 30th July the following year.