COPTOS, the modern Kobt or Koft, a town of Egypt, a short distance from the right bank of the Nile, about 25 miles north-east of Thebes. It is a place of great antiquity, as is proved by the name of Thothmes HI. still extant cn a granite pillar, but its ruins for the most part belong to a comparatively late period. After the foundation of the port of Berenice on the Red Sea in 266 b.c., its position on the caravan line raised it to great commercial prosperity; but in 292 A.D. its share in the rebellion against Diocletian led to an almost total devastation. It again appears, however, as a place of importance, and as the seat of a considerable Christian community, though the stream of traffic turned aside to the neighbouring Koos. During part of the 7th century it was called Justinianopolis in honour of the Emperor Justinian.