Yotvingia
Yotvingia (Polish: Jaćwież, Lithuanian: Jotva, Belarusian: Яцьвезь (Ятвязь, Етвязь), old Russian: Ятвягия) was a region where the Baltic tribe known as Yotvingians lived. It was located in the area of Sudovia and Dainava; south west from the upper Neman, between Marijampolė, Merkinė (Lithuania), Slonim, Kobryn (Belarus), Białystok, and Ełk (Poland);
Today this area corresponds mostly to the Podlaskie Voivodeship of Poland, part of Lithuania and a part of Hrodna Province and Brest Province of Belarus.
History
The Treaty of 944 between Kievan prince Igor and the Byzantine Empire has the names of many Rus' ambassadors - one of which was Jatviag Gunarev. It is also the first written documentation of the term Jatviag, or Yatviag.
The southern part of the Yotvingian lands, Sudovia and Galindia, were subdued by Kievan Rus' army, led by Vladimir I of Kiev in 983.
Netimeras, a ruler of the Yotvingians, was converted to Christianity by Bruno of Querfurt in 1009.
When his father died in 1170, Roman the Great was bequeathed the Principality of Vladimir-in-Volhynia. He subdued the Yatvingians, and harnessed the captives instead of oxen to drag the plows on his estates.