Old Prussians, Baltic Prussians or simply Prussians were a Baltic people that inhabited the region of Prussia, on the southeastern shore of the Baltic Sea between the Vistula Lagoon to the west and the Curonian Lagoon to the east. As Balts, they spoke an Indo-European language of the Baltic branch now known as Old Prussian and worshipped pre-Christian deities. Their ethnonym was later adopted by predominantly Low German-speaking inhabitants of the region.