 Complete the following phrase:  In the 12th century the lower Łeba marked the eastern border of the Land of Słupsk-Sławno, ruled by the Pomeranian Griffin duke Ratibor I and his descendants, while the territory around the castellany of Białogarda was a possession of the Pomerelian duke Sobieslaw I of the Samborides dynasty. After Poland regained Pomerelia in 1294, the Łeba formed the boundary between the Polish part of Pomerania and the Duchy of Pomerania. From 1308, after the Teutonic takeover of Danzig Gdańsk and the 