ポロツク公国
In the first decade of the 13th century the Principality of Jersika, also known as "Lettia", was allied with the Principality of Polotsk and Lithuanian dukes against the Bishopric of Livonia, but was defeated in 1209. Part of it was divided between the Bishopric and the Livonian Brothers of the Sword, the remainder became a vassal country. In 1239, after the death of King Visvaldis, the latter was incorporated into the territory of the Livonian Order.