By the eleventh century a fortress named Dirlow, (or Dirlovo) existed where the River Wieprza entered the Baltic.
From this fortress, the district of Dirlow was administered, which belonged to the castelany of Sławno.
A town was later founded in the district of Dirlow, but not at the location of the fortress itself.

The town was probably founded in 1270 by Wizlaw II of the Danish Principality of Rügen, at that time also ruler of the Lands of Schlawe and Stolp.
The first mention of the town is in a document of 5 February 1271.
The settlement decayed.

The town was destroyed in 1283 during a conflict between Wizlaw II and Mestwin II (Polish: Mszczuj or Mściwój).
In a chronicle of 1652, Matthäus Merian stated that the town had been destroyed by Bogislaw of Pomerania, when after Mestwin's II death in December 1294 the Duke Przemysł II (future king) of Poland acquired the town, as a consequence of Treaty of Kępno.

The town was rebuilt and on 21 May 1312, the town was granted Lübeck law under the administration of the noble brothers John, Peter, and Lawrence of the Swienca family, vassals of the Brandenburg margraves since 1307.
The Brandenburg margraves undertook in 1308 a campaign against Gdańsk.

The town passed to the Duchy of Pomerania in 1347, at that time ruled by the brothers Bogislaw V, Wartislaw V, and Barnim IV of the House of Pomerania dynasty.
Bogislaw, son-in-law of king Casimir III of Poland, would become ruler of the area after the partition of Pomerania-Wolgast in 1368.
This part duchy was known as Pomerania-Stolp (Duchy of Słupsk).
Duke Bogislaw VIII, a Polish vassal, tried to direct Polish Baltic trade to the port of Darłowo, but without success.
By the eleventh century a fortress named Dirlow, (or Dirlovo) existed where the River Wieprza entered the Baltic. From this fortress, the district of Dirlow was administered, which belonged to the castelany of Sławno. A town was later founded in the district of Dirlow, but not at the location of the fortress itself.
The town was probably founded in 1270 by Wizlaw II of the Danish Principality of Rügen, at that time also ruler of the Lands of Schlawe and Stolp. The first mention of the town is in a document of 5 February 1271. The settlement decayed.
The town was destroyed in 1283 during a conflict between Wizlaw II and Mestwin II (Polish: Mszczuj or Mściwój). In a chronicle of 1652, Matthäus Merian stated that the town had been destroyed by Bogislaw of Pomerania, when after Mestwin's II death in December 1294 the Duke Przemysł II (future king) of Poland acquired the town, as a consequence of Treaty of Kępno.
The town was rebuilt and on 21 May 1312, the town was granted Lübeck law under the administration of the noble brothers John, Peter, and Lawrence of the Swienca family, vassals of the Brandenburg margraves since 1307. The Brandenburg margraves undertook in 1308 a campaign against Gdańsk.
The town passed to the Duchy of Pomerania in 1347, at that time ruled by the brothers Bogislaw V, Wartislaw V, and Barnim IV of the House of Pomerania dynasty. Bogislaw, son-in-law of king Casimir III of Poland, would become ruler of the area after the partition of Pomerania-Wolgast in 1368. This part duchy was known as Pomerania-Stolp (Duchy of Słupsk). Duke Bogislaw VIII, a Polish vassal, tried to direct Polish Baltic trade to the port of Darłowo, but without success.
Darłowo