sentences:  The exact borders of the territory are unknown, nor its status as an Imperial estate.Four years later, Bogusław had to submit to King Canute VI of Denmark.The term Duchy of Slavinia was sometimes used to denote the Griffin Duchy of Pomerania, located at the mouth of the Oder and ruled by the descendants of Duke Wartislaw I from the early 12th century, from the Pomerelian lands in the east under the rule of the Samborides initially as Polish vassals and also called "Duchy of Pomerania" at that time.