Ukrainian (ukrayins'ka mova) is a language of the East Slavic sub-group of the Slavic languages. It is the official state language of Ukraine, in the Ukrainian-speaking areas of Russia is known as Balachka or Surzhyk. The language shares some vocabulary with the languages of the neighboring Slavic nations, mainly with Polish, Slovak in the West and Belarusan, Russian in the North and the East. The Ukrainian language traces its origins to the Old Slavic language of the early medieval state of Kievan Rus'. In its earlier stages it was called Ruthenian. Ukrainian is a lineal descendant of the colloquial language used in Kievan Rus (10th–13th century). The language has persisted despite several periods of bans and/or discouragement throughout centuries as it has always maintained a sufficient base among the people of Ukraine, its folklore songs, itinerant musicians, and prominent authors.