There has, fairly recently, been a revival of the Prussian Language and Heritage.  The Prussians (Prusa is the original non-latinized version) were the indiginous people of the Baltic region around Danzig.  Eventually, they were invaded by and christianized by the German Order of Knights. This christianized nation forced its ruling society and military to speak German rather than Prussian, which was still spoken by the common people.  When a massive plague ripped through the region, it wiped out most of the remnants of the language, and so today it is considered a DeadLanguage. A great resource for the "reconstruction" of Prussian is  Input by JoCaGo
*** http://poshka.bizland.com/prussian/reconstructions.htm