The Ruthenian population formed a majority in GDL from the time of the GDL's expansion in the mid 14th century; and the adjective "Lithuanian", besides denoting ethnic Lithuanians, from early times denoted any inhabitant of GDL, including Slavs and Jews.
The Lithuanian National Revival had begun to intensify by the end of the 19th century, and the number of Lithuanian speakers and people identifying themselves as ethnic Lithuanians started to increase; but at the same time many Polish speaking Lithuanians, especially former szlachta, cut themselves adrift from the Lithuanian nation.