The Principality of Jersika was a medieval principality in the east of modern-day Latvia, and one of the largest medieval states in Latvia before the Northern Crusades. The capital of Jersika was located on a hill fort 165 kilometres (103 mi) southeast of Riga.

Latvia, officially the Republic of Latvia, is a country in the Baltic region of Northern Europe. It is one of the three Baltic states, along with Estonia to the north and Lithuania to the south. It borders Russia to the east, Belarus to the southeast, and shares a maritime border with Sweden to the west. Latvia covers an area of 64,589 km2 (24,938 sq mi), with a population of 1.9 million. The country has a temperate seasonal climate. Its capital and largest city is Riga. Latvians belong to the ethnolinguistic group of the Balts and speak Latvian, one of the only two surviving Baltic languages, a branch of the Indo-European language family. Russians are the most prominent minority in the country, at almost a quarter of the population.