Ukrainian (украї́нська мо́ва / ukrayins'ka mova, [ukrɑˈjɪɲsʲkɑ ˈmɔvɑ], formerly Ruthenian - ру́ська, руси́нська мо́ва / rus'ka, rusyns'ka mova) is a member of the East Slavic subgroup of the Slavic languages. It is the official state language of Ukraine and the principal language of the Ukrainians. Written Ukrainian uses a variant of the Cyrillic script.
The Ukrainian language traces its origins to the Old East Slavic of the early medieval state of Kievan Rus'. Ukrainian is a lineal descendant of the colloquial language used in Kievan Rus' (10th–13th century). From 1804 until the Russian Revolution Ukrainian was banned from schools in the Russian Empire of which Ukraine was a part at the time. It has always maintained a sufficient base in Western Ukraine where the language was never banned in its folklore songs, itinerant musicians, and prominent authors.
The standard Ukrainian language is regulated by the National Academy of Sciences of Ukraine (NANU), particularly by its Institute for the Ukrainian Language, Ukrainian language-informatical fund, and Potebnya Institute of Language Studies. Ukrainian, Russian, Belarusian, and Rusyn have a high degree of mutual intelligibility.