Sudovian

The Sudovians, also called the Yotvingians, were a Western Baltic people of Sudovia or Dainava, in the forests south-west of the upper Nemunas. Ptolemy placed the Soudinoi there in the second century, and Rus chronicles knew them as warriors who served the princes of Kiev. Related to the Old Prussians, they were credited with six thousand cavalry by Peter of Dusburg.

They joined the Prussian rising against the Teutonic Order and under their leader Skalmantas raided Culmerland and Pinsk in the 1270s. The Order's campaigns of 1277 to 1283 broke them: in 1283 some sixteen hundred surrendered and were resettled in Samland, others were moved to Pogesania, and Sudovia was left an unpopulated border wilderness.

Many who escaped fled to Lithuania, joining the Lithuanian nation whose early state they helped form; those transplanted into Prussia gradually adopted their conquerors' speech and faith.