 Around 1310, when he was about 23, Ockham began his theological training. It is not certain where this training occurred. It could well have been at the London Convent, or it could have been at Oxford, where there was another Franciscan convent associated with the university. In any event, Ockham was at Oxford studying theology by at least the year 1318–19, and probably the previous year as well, when (in 1317) he began a required two-year cycle of lectures commenting on Peter Lombard’s Sentences, the standard theological textbook of the day. Then, probably in 1321, Ockham returned to London Greyfriars, where he remained. Although he had taken the initial steps in the theology program at Oxford (hence his occasional nickname, the Venerabilis Inceptor, “Venerable Beginner”), Ockham did not complete the program there, and never became a fully qualified “master” of theology at Oxford. Nevertheless, London Greyfriars was an intellectually lively place, and Ockham was by no means isolated from the heat of academic controversy. Among his “housemates” were two other important Franciscan thinkers of the day, Walter Chatton and Adam Wodeham, both sharp critics of Ockham’s views. It was in this context that Ockham wrote many of his most important philosophical and theological works.