After having viewed the Pontus, Darius sailed back to the bridge, whose architect was Mandrocles of Samos; and when he had viewed the Bosporus also, he set up two pillars of white marble by it, engraving on the one in Assyrian and on the other in Greek characters the names of all the nations that were in his army: all the nations subject to him. The full census of these, over and above the fleet, was seven hundred thousand men, including horsemen, and the number of ships assembled was six hundred. These pillars were afterward carried by the Byzantines into their city and there used to build the altar of Orthosian Artemis, except for one column covered with Assyrian writing that was left beside the temple of Dionysus at Byzantium. Now if my reckoning is correct, the place where king Darius bridged the Bosporus was midway between Byzantium and the temple at the entrance of the sea.