Pomerania, historic region of northeastern lying along the Baltic coastal plain between the Oder and the Vistula rivers. Politically, the name also came to include the area west of the Oder as far as , including the island of (Rugia). Most of Pomerania is now part of , but its westernmost section is in eastern , as reflected in the name of Mecklenburg-West Pomerania Land (state). The region is generally flat, and there are numerous small rivers and, along the east coast, many lakes.Pomerania was inhabited successively by Celts, Germanic tribes, and, by the 5th century ce, the Slavic Pomeranians (Pomorzanie) and Polabs. , prince of Poland (died 992), mastered it, and in 1000 his successor, the Brave, organized a diocese in Pomerania with its seat at . A local dynasty then ruled Pomerania and also the region to the west, later called Mecklenburg. German immigration into the western and central regions of Pomerania began in the late 12th century. This resulted in the Germanization of the towns and later of the nobility and the countryside.Until the 17th century, Polish dukes ruled western and central Pomerania (the duchies of Wolgast and Stettin) under the suzerainty of the . The elector of acquired these duchies in 1637, when the last Polish duke, Bogusław XIV, who had united them, died without issue. Sweden received Western Pomerania by the (1648); part of it was returned to Brandenburg- in 1720, and the remainder (Stralsund and Rügen) was recovered by Prussia in 1815. Prussia united western and central Pomerania into one province called Pommern., Pomerania (Polish: Pomorze [pɔˈmɔʐɛ] ⓘ; German: Pommern ⓘ; Kashubian: Pòmòrskô; Swedish: Pommern) is a historical region on the southern shore of the Baltic Sea in Central Europe, split between Poland and Germany., Pomerania, historic region of northeastern Europe lying along the Baltic coastal plain between the Oder and the Vistula rivers. Politically, the name also came to include the area west of the Oder as far as Stralsund, including the island of Rügen (Rugia)..