Histories

From there they rounded the head of the Black Bay (as it is called) and crossed the Black River, which could not hold its own then against the army, but gave out—crossing this river, which gives its name to the bay, they went westwards, past the Aeolian city of Enez [26.83,40.733] (inhabited place), Edirne, Marmara, Turkey, AsiaAenus and the marsh of Stentor, until they came to Doriscus.

The territory of Doriscus is in Thrace (region (general)), EuropeThrace, a wide plain by the sea, and through it flows a great river, the +Maritsa [26.2,40.866] (river), Europe Hebrus; here had been built that royal fortress which is called Doriscus, and a Persian guard had been posted there by Darius ever since the time of his march against Scythia (region (general)), AsiaScythia.