Nikephoros Kallistos Xanthopoulos

Nikephoros Kallistos Xanthopoulos (c. 1256–1335) was a Byzantine priest of Hagia Sophia and ecclesiastical historian born in Constantinople. Granted access to the patriarchal library, he began his twenty-three-book Church History around 1310 and completed it after 1317, dedicating it to Andronikos II Palaiologos.

The surviving eighteen books run from Christ to the death of Emperor Phokas in 610, drawing on Eusebios and earlier historians. He also taught rhetoric and wrote saints' lives, synaxaria and religious poems.