Nicephorus Gregoras was a Byzantine astronomer, historian, and theologian. His 37-volume Roman History, a work of erudition, constitutes a primary documentary source for the 14th century. 1295 – 1360; died at about 64. Alive at the same time as Dante Alighieri, Marco Polo, William of Ockham, Giotto, and Edward I of England. Wiki link