Semigalian language
 
When the modern Lativan nations was only a set of different tribal languages, the most important of them were Latgalian, Zemgalian, Curonian. Semigalians or Zemgalians (Zemgola in Russian) used to live in the central parts of Latvia, north to the Daugava (Dvina) river. They went through the initial feudalism forming and in the 12th century together with Latgalians founded two little principalities: Talava and Gertsike, the last governed by Russian princes. Semigalians had close relations with Eastern Slavs, further Kiev Russia, Lithuanian principalities and ordered with Livonians and Estians, who lived north to them.

In the beginning of the 13th century the epoch of German Crusades to the Eastern Europe started. That meant first of all invasions to Baltic lands, and though Semigalians were not the first to suffer the intrusion, soon they had to fight. Teutonic Knights conquered the lands of Prussians, Curonians, and in 1212 came to Semigalia. In two years the struggle of Semigalians was suppressed, and in 1214 Talava principality was conquered.

The Semigalian language carried several features characteristic also to Curonian and somehow close to Latvian.  Common Baltic k, g in their soft variety bacame c, dz in Semigalian. All long vowels and diphthongs at the end of the word were reduced to simple short vowels.

Semigalian vocabulary used many Slavic words, also some were borrowed from Livonian and Estian, Finnish languages.