Latgalians

Latgalians (, , modern ; variant translations also include Latgallians, Lettigalls or Lettigallians) were an ancient Baltic tribe.

They likely spoke a variant of Latvian language, which probably became the lingua franca in present-day Latvia during the Northern Crusades due to their alliance with the crusaders. Latgalians later integrated with the neighbouring tribes, forming the core of modern Latvians.