Tmutarakan or Tmutorakan was the name of a Mediaeval Kievan Rus' principality and trading town that controlled the Cimmerian Bosporus, the passage from the Black Sea to the Sea of Azov. Its site was the ancient Greek colony of Hermonassa , situated on the Taman peninsula, in the present-day Krasnodar Krai of Russia, roughly opposite Kerch. The Khazar fortress of Tamantarkhan (from which the Byzantine name for the city, Tamatarcha, is derived) was built on the site in the 7th century and became known as Tmutarakan (, ) when it came under Kievan Rus control in the 10th and 11th centuries.