Nicomedia, Bithynia (in Asia Minor, on the Black Sea) was described by ancient writers as a city of superior size and magnificence, ranking next to Rome, Alexandria, and Antioch in the splendor and beauty of its buildings. Diocletian worked to make Nicomedia the equal of Rome itself. Dates of operation: 294 - c. 474 A.D. (reopened as a Byzantine mint, 498 - 627). Mintmarks: MN, N, NIC, NICO, NIK, SMN.