What is "pogesanians"

Pogesanians were one of the eleven Prussian clans mentioned by Peter von Dusburg. The clan lived in Pogesania (; ; ; ), a small territory stretched between the Elbląg and Pasłęka rivers. It is now located in the Warmian-Masurian Voivodeship, northern Poland. Pogesanians, as the rest of the Prussians, were conquered by the Teutonic Knights and became Germanized or polonized. The old Prussian language became extinct sometime in the 17th century.