During his tenure, he amassed a great fortune, especially estates in Macedonia, through bribes, the selling of offices and tax farming. These practices were quite common among the Palaiologan bureaucracy, whose corrupt administration was especially burdensome on the Empire's subjects. Part of this fortune was used in the establishment and endowment of the monastery of the Theotokos Gorgoepekoos in Constantinople. In 1309–1310 Choumnos served as governor of the Empire's second-largest city, Thessalonica, but thereafter withdrew from public office. During the 1320s, he engaged in a protracted exchange of polemics with his chief intellectual and political rival, Theodore Metochites. While Choumnos derided his opponent's lack of clarity, Metochites attacked Choumnos' disinterest in physics and his ignorance of astronomy, which he held as the "highest form of science". In ca. 1326, Choumnos retired as a monk, under the monastic name Nathanael, to the monastery of Christ Philanthropos in Constantinople, which had been founded by his daughter Eirene. There he died on 16 January 1327. Writings Choumnos was a prolific writer, greatly influenced by the Classics, which he had studied as a young pupil. His works, several of which remain unpublished, include rhetorical pieces, such as the eulogy to Andronikos II, as well as treatises on philosophy, especially on elemental theory, meteorology, cosmology and theology. Several of these treatises often appear to have been composed on the occasion of literary gatherings within the court, sometimes with the emperor presiding. From his extensive correspondence, 172 letters survive. In his philosophical works, Choumnos proves himself an "ardent and skillful" defender of Aristotle. Nevertheless, he does not embrace Aristotelianism, but is rather interested to provide a rigidly rational philosophical justification for the doctrines held by Christian theology. In his attacks on the Platonic theories of substance and forms or in his refutation of Plotinus' theories on the soul, Choumnos tries to prove Christian theological teaching. According to the French Byzantinist Rodolphe Guilland, "by his love of antiquity, passionate, although a little servile, and by the variety of his knowledge Choumnos heralds Italian humanism and the western Renaissance." Family Nikephoros' brother Theodore was also a court official. From his marriage to an unknown wife, Choumnos had several children: John Choumnos, (chamberlain) and general. George Choumnos, (head of the imperial table) and (grand master of the camp). Irene Palaiologina Choumnaina, married the John Palaiologos. Following his death in 1308, and having no children, she became a nun by