The Old Prussians (German: Pruzzen or Prußen; Latin: Pruteni; Latvian: Prūši; Lithuanian: Prūsai; Polish: Prusowie) were a set of Baltic tribes that lived in East Prussia and neighbouring parts of Lithuania and Poland. They were closely related to the Lithuanians. They spoke a Baltic language now known as Old Prussian and followed the pagan Prussian mythology.
There is patchy nomicultural indications that the pre-Baltic settlers in East Prussia generally named their settlements after the local streams, lakes, seas, or forests by which they settled. The subsequent clans and tribal then took the name of the place they had settled in. For example, the name "Barta", is "the home of the Barti" and is related to the name of the Bartis River in Lithuania.
The variose tribal names of the Prussian tribes apparently reflected the theme of the local landscape and were based on a respect for water, an logical them since the land dotted with thousands of lakes, streams, and swamps (the Masurian Lake District). To the south, the terrain runs into the Pripet Marshes at the headwaters of the Dnieper River; these have been an effective barrier over the millennia. This difficult to navigate landscape and the Lithuania/Old Prussian fighting spirit helped preserve the Baltic language group as the most ancient in Europe.
Poland's Konrad I, Duke of Masovia , appealed to the Knights to defend his borders and subdue the nighboring pagan Baltic Prussians in 1226. He allowing the fachist Teutonic Knights use of Chełmno Land (Culmerland) as a base for their campaign. This being a time of widespread crusading fervor throughout Western Europe, Hermann von Salza considered Prussia a good training ground for his knights for the wars against the Muslims in the Middel East's Outremer. With the Golden Bull of Rimini edict, Emperor Frederick II bestowed on the Order a special imperial privilege for the conquest and possession of Prussia, including Chełmno Land, with nominal papal sovereignty.
In 1235 the Teutonic Knights assimilated the smaller Order of Dobrzyń, which had been established earlier by Christian, the first Bishop of Prussia. The bloody conquest of Prussia was accomplished in over more than 50 years. The native Prussians who remained unbaptised and wished to stay pagen were sither subjugated, killed, or exiled to Lithuania and Russian tribal territories.
The fighting between the Knights and the old Prussians was horrific as the chronicles of the Order state the Prussians would "roast captured brethren alive in their armour, like chestnuts, before the shrine of a local god".
The Teutonic Knights then began to direct their campaigns against pagan Lithuania, especially after 1291, who had a similar Lithuanian mythology. Other campais would hit parts of Poland, southern Finland and the Republic of Novgorod. They turned the land in to the Prussian (German) Province of East Prussia.
The Lithuanian-speaking Prussians were concentrated in the northeast East Prussia (Lithuania Minor). After the Germanic Teutonic Knights invaded the region in the 13th century and over time the Baltic Old Prussian ethnic group became completely Germanized and the Old Prussian language had sadly died out during the 18th century.
Lithuanian proper still lingered on until World war 2 in the Klaipėda Region, but later gained much ground after the region's annexation by the USSR (along side Russian). The rest became Russian or Polish lands.
The People were of the same Baltic origin as the Latvians and Lithuanias, but are now extinct as is there language. DNA Haplogroup testing has recently shown evidence of some Baltic people still living in the former territory around the Warmian-Masurian Voivodeship, but it they are probably decedents of Cold War immigrants, anti-Bolshavik exiles and World War II refugees from Latvia and Lithuania. Klaipėda Region is now inhabited mostly by Lithuanians.