Their origin itself is a mystery too. It was firstly mentioned in the IX century in the records of an anonymous merchant and later in Polish and German chronicles. Linguists find its analogies in various Indo-European languages and believe it to trace back to Sanscrit purusa, “man”.
It is not much know about their language. The final native died in 1677, while the plague of 1709-1711 killed the last Prussians in Prussia itself. In the XVII began the history of Prussianism and the Prussian Kingdom whose people had little in common with the original Baltic Prussians.