Between the Black Sea, the Bosphorus, and the River Barbyses, which is deep in summer, and runs fifteen miles through a flat meadow. Its communication with Europe and Constantinople is by the stone bridge of the Blachernae, which in successive ages was restored by Justinian and Basil (Gyllius de Bosphoro Thracio, l. ii. c. 3. Ducange O. P. Christiana, l. v. c. 2, p, 179).