Semigallia is a historical Latvian land located in the Baltic region. It is situated to the south of the Daugava River and to the north of the Saule region of Samogitia. The territory currently spans across the borders of Latvia and Lithuania.
The area was historically inhabited by the Semigallian Baltic tribe, who maintained close linguistic and cultural ties with the Samogitians. The Semigallians are notably recognized for their prolonged resistance against German crusaders and Teutonic Knights during the Northern Crusades between 1219 and 1290.