Of the numerous colonies sent out by the Greeks, we shall notice only those which were established for the purposes of commerce, or which, though not established for this express purpose, became afterwards celebrated for it. None of the Athenian colonies, which they established expressly for the purpose of trading with the capital, was of such importance as Amphipolis. This place was situated at the mouth of the river Strymon, on the borders of Macedonia. The country in its vicinity was very fertile in wood, and from it, for a considerable length of time, the Athenians principally derived timber for building their fleets: they also levied on its inhabitants a heavy tribute in silver coin. As this city was well situated for commerce, and the Athenians, wherever they went, or were settled, were eager in pursuit of gain, their colonists in Amphipolis extended their trade, on one side into Thrace, and on the other into Macedonia. They were enabled, in a great measure, to monopolize the commerce of both these countries, at least those parts of them which were contiguous, from the situation of their city on the Strymon; of which river they held, as it were, the key, so that nothing could depart from it without their consent. The ancients represent this river as frequently exhibiting immense logs of wood floating down it, which had been felled either on Mount Rhodope, or in the forests of Mount Hemus. The Athenians retained this important and valuable colony till the time of Philip, the father of Alexander, by whom it was taken from them.