History of the Peloponnesian War

Setting out then from the Odrysians, he summoned to his standard, first the Thracians within Mount Haemus and Rhodope, as many as were subject to him, as far as the coast of the Euxine and the Hellespont; next the Getae beyond Haemus, and all the other hordes that were settled [*]( Literally, within the Danube. ) south of the Danube, more towards the sea-board of the Euxine; the Getae and the tribes in this part being both borderers on the Scythians, and equipped in the same manner, for they are all mounted bowmen.

He also invited many of the Highland Thracians, who are independent, and armed with swords; they are called the Dii, and are mostly inhabitants [of the valleys] of Haemus: some of these he engaged as mercenaries, while others followed him as volunteers.

Moreover, he summoned the Agrianians and Laeaemans and all the other Paeonian tribes that acknowledged his sway. And these were the last people in his dominion, for at the Graaeans and Laeaeans, both of them Paeonian tribes, and at the river Strymon, which flows from Mount Scomius through their country, his empire terminated on the side of the Paeonians, who from this point were independent.

On the side of the Triballi, who were also independent, the border tribes were the Treres and Tilataeans, who live to the north of Mount Scombrus, and stretch towards the west as far as the river Oscius. This river flows from the same mountain as the Nestus and the Hebrus, an uninhabited and extensive range, joining on to Rhodope.