On 7 March 1528, Cuthbert Tunstall, bishop of London, sent a letter to Thomas More asking him to write against heresy. Tunstall pointed out that heretical literature of both German and English authorship was coming into England in such quantities that, unless good and learned men could be found to confute these heretical books in English, the Catholic faith in England would be in grave danger. He was entrusting More with this task, the bishop concluded, because More was a master of eloquence in English as well as in Latin.
When More decided to carry out Tunstall's commission in dialogue form, he was not satisfying the predilections for the dramatic he had already evinced in his Richard the Thirde and Utopia but was availing himself of a weapon proven potent in the art of religious and secular controversy.