Mandrocles bridged the fish-teeming Bosphorus, he dedicated this picture to Hera in remembrance of the floating bridge. He obtained the crown, the glory of the Samians, in that he completed the work to the satisfaction of King Darius."[263] It was in the year 513 B.C. that the armies of Asia trod the soil of Europe.[264] The fleet was ordered to sail along the Thracian coast in the Pontus, then to enter the mouth of the Danube, and there prepare means for the army to cross the river, by procuring supplies, and constructing a bridge, no easy task considering the breadth and rapidity of the stream. The sovereigns of the Greek cities, who owed their elevation to the Persian king, commanded their ships in person, as Darius had taken the field in person, or entrusted them to their sons. Thus Histiaeus the son of Lysagoras, the sovereign of Miletus, which was the most powerful of the Greek cities of the coast, commanded his own ships, Laodamas the ships of Phocaea, Aeaces the son of Syloson the ships of Samos, Strattis the ships of Chios, Aristagoras the ships of Cyzicus, Metrodorus those of Proconnesus in the Propontis, Daphnis the ships of Abydus. The ships of Lampsacus were in the charge of Hippoclus, those of Parium in the charge of Herophantus; and lastly, the sovereigns of the recently-conquered districts, Ariston and Miltiades, commanded the ships of Byzantium, of Sestos, and Cardia. While the fleet sailed to the Danube, the land army marched for two days from the coast, to the north, in the direction of the Balkan. At the sources of the Tearus, which no doubt are those of the Simir dere, which near Bunar Hissar send up warm and cold springs--thirty-eight in number according to Herodotus--the army rested three days; Darius caused a monument to be erected with an inscription, which Herodotus gives thus: "The springs of the Tearus supply the best and purest water of all rivers, and to these on his march against the Scyths came the bravest and most handsome of men, Darius the son of Hystaspes, the king of the Persians and of all the mainland."[265]