Despite political decline during the late 12th and much of the 13th centuries, the Byzantine scholarly tradition remained particularly fruitful over the time period. One of the most prominent philosophers of the 11th century, Michael Psellos, reinvigorated Neoplatonism on Christian foundations and bolstered the study of ancient philosophical texts, along with contributing to history, grammar, and rhetorics. His pupil and successor at the head of Philosophy at the University of Constantinople Ioannes Italos continued the Platonic line in Byzantine thought and was criticized by the Church for holding opinions it considered heretical, such as the doctrine of transmigration. Two Orthodox theologians important in the dialogue between the eastern and western churches were Nikephoros Blemmydes and Maximus Planudes. Byzantine historical tradition also flourished with the works of the brothers Niketas and Michael Choniates in the beginning of the 13th century and George Akropolites a generation later. Dating from 12th century Byzantine Empire is also Timarion, an Orthodox Christian anticipation of Divine Comedy. Around the same time the so-called Byzantine novel rose in popularity with its synthesis of ancient pagan and contemporaneous Christian themes.