The Latvians are a Baltic people culturally related to the Estonians and Lithuanians, with the Latvian language having many similarities with Lithuanian, but not with the Estonian language. Today the Latvian and Lithuanian languages are the only surviving members of the Baltic languages of the Indo-European family. The modern name of Latvia is thought to originate from the ancient Latvian name Latvji, which, like the name of Lithuania, may have originated from the river named Latva or Latuva, which may be today's Lates upe.