Old Rus' literature, also known as Old Russian literature or Old East Slavic literature, is a collection of literary works of Old Rus' authors, which includes all the works of ancient Rus' theologians, historians, philosophers, translators, etc., and written in Old East Slavic. It is a general term that unites the common literary heritage of Russia, Belarus and Ukraine of the ancient period. In terms of genre construction, it has a number of differences from medieval European literature. The greatest influence on the literature of ancient Rus' was exerted by old Polish and old Serbian literature.