Nicephorus Gregoras (/ˈɡrɛɡərəs/; Greek: Νικηφόρος Γρηγορᾶς, Nikēphoros Grēgoras; c. 1295 – 1360) was a Byzantine Greek[1] astronomer, historian, and theologian. His 37-volume Roman History, a work of erudition, constitutes a primary documentary source for the 14th century.