Ancient district, eastern Anatolia. It is a mountainous area located in modern-day Turkey; its earliest records date from the 6th century BC, when it was a Persian satrapy. It became a semi-independent kingdom under Ariarathes I, a contemporary of Alexander the Great. Important as a Roman ally and client, it was annexed by the emperor Tiberius in AD 17 and made a Roman province. With its command over strategic passes in the Taurus Mountains, the area was a bulwark of the Byzantine Empire until the 11th century