Where was Old Prussian spoken?

The Old Prussian language was spoken in the region historically known as East Prussia, an area that now corresponds to parts of Poland and Russia.1

Geographically, the indigenous Prussians inhabited the heavily forested region situated between the lower Vistula and Neman rivers along the southeastern coast of the Baltic Sea. While the language was once widespread among the local tribes, the region underwent significant demographic changes following the 13th-century conquest by the Teutonic Order. Although the area became increasingly German-speaking by the mid-14th century, the Old Prussian language persisted until it finally became extinct in the 17th century.2