When did written literature in the Russian language begin to develop?

Written literature in the Russian language began to develop with the Christianization of Kievan Rus in the late 10th century. Following this conversion, the region established its own scribal activities, primarily focused on copying and translating religious texts from Greek into Old Church Slavonic, which served as the literary language of the period.123

The oldest dated Russian manuscript is The Ostromir Gospel (Ostromirovo evangeliye), produced in 1056–57. During this early Kievan period, literary output consisted largely of ecclesiastical works, such as the Gospels, homilies, and hagiographies, alongside some secular chronicles and tales. While some 19th-century critics argued that Russian literature did not begin until the reforms of Peter I in the 18th century, modern scholarship recognizes this earlier body of work as the foundation of the literary tradition.341