Prussians
The first time the Prussians are mentioned only in the IX century under the name Brusi in the letters of the anonymous merchant and later in Polish and German chronicles.
Linguists find them similar in many Indo-European languages and think that they go back to Sanskrit purusa, «people». There isn’t preserved any sufficient information about the language of the Prussians. The last habitant died in 1677, and the plague of 1709 – 1711’s destroyed the last of the Prussians in Prussia.
