Belarus–Ukraine relations
Belarus–Ukraine relations (, "Byelaruska-ŭkrainskiya adnosiny", , "Ukrains'ko-Bilorus'ki vidnosyny", , "Belorussko-ukrainskiye otnosheniya") are foreign relations between Belarus and Ukraine. Both countries were successively ruled by the Polish-Lithuanian Commonwealth, the Second Polish Republic, and ultimately, the Russian Empire. Prior to the 1991 breakup, both countries were part of the Soviet Union as the Belarusian SSR and Ukrainian SSR when they were the founding members of the United Nations in 1945. Being Slavic nations, both Belarus and Ukraine share closely related cultures and are predominantly inhabited by the East Slavic ethnic groups of Belarusians and Ukrainians respectively, along with a few Russians. Today, the two countries share an 891–km border.
Ukrainian language
Some scholars see a divergence between the language of Galicia-Volhynia and the language of Novgorod-Suzdal by the 12th century, assuming that before the 12th century, the two languages were practically indistinguishable. This point of view is, however, at variance with some historical data. In fact, several East Slavic tribes, such as Polans, Drevlyans, Severians, Dulebes (that later likely became Volhynians and Buzhans), White Croats, Tiverians and Ulichs lived on the territory of today's Ukraine long before the 12th century. Notably, some Ukrainian features were recognizable in the southern dialects of Old East Slavic as far back as the language can be documented.