Page "Bosphorus" Paragraph 11

Persian King Darius I the Great, in an attempt to subdue the Scythian horsemen who roamed across the north of the Black Sea, crossed through the Bosphorus, then marched towards the Danube River.

His army crossed the Bosphorus over an enormous bridge made by connecting Achaemenid boats.

This bridge essentially connected the farthest geographic tip of Asia to Europe, encompassing at least some 1000 meters of open water if not more.

Years later, a similar boat bridge would be constructed by Xerxes I on the Dardanelles ( Hellespont ) strait, during his invasion of Greece.

Byzantines called the Bosphorus " Stenon " and most important toponyms of it Bosphorios Akra, Argyropolis, St. Mamas, St. Phokas, Hestiai or Michaelion, Phoneus, Anaplous or Sosthenion in European side and Hieron tower, Eirenaion, Anthemiou, Sophianai, Bithynian Chryspolis in Asian side in this era