History of the Peloponnesian War

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.

The extent then of the Odrysian dominion, taking the line of its sea-coast, was from the city of Abdera to the Euxine, up to the mouth of the Danube. This tract is by the shortest way a voyage of four days and nights for a merchant-vessel, supposing the wind to be always steady astern. By land, taking the shortest way from Abdera to the [mouth of] the Danube, a quick traveller performs the journey in eleven days.

Such was the extent of its sea-board. As for the in terror, from Byzantium to the Laeaeans and the Strymon, (for at this point it reached its greatest extent up the country from the sea,) for a quick traveller it was a journey of thirteen days.