Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Old Prussians or Baltic Prussians (German: Pruzzen or Prußen; Latin: Pruteni; Latvian: Pr i; Lithuanian: Pr sai; Polish: Prusowie) were an ethnic group, autochthonous Baltic tribes that inhabited Prussia, the lands of the southeastern Baltic Sea in the area around the Vistula and Curonian Lagoons. They spoke a language now known as Old Prussian and followed a religion believed by modern scholars to be closely related to Lithuanian paganism with such gods as Perk ns.