What is "yotvingians"

Yotvingians or Sudovians (also called Suduvians, Jatvians, or Jatvingians in English) (; ; , , ) were a Baltic people with close cultural ties in the 13th century to the Lithuanians and Prussians. The Yotvingian language (sometimes called Sudovian) was a Western Baltic language nearest to Prussian, but with small variations. They were referred to in regional historical records into the 19th century.