Новгородская первая летопись
Historical documents about Slavic religion include the "Primary Chronicle", compiled in Kyiv around 1111, and the "Novgorod First Chronicle" compiled in the Novgorod Republic. They contain detailed reports of the annihilation of the official Slavic religion of Kyiv and Novgorod, and the subsequent "double faith". The "Primary Chronicle" also contains the authentic text of Rus-Greek treatises (dated 945 and 971) with native pre-Christian oaths. From the eleventh century onwards, various Rus writings were produced against the survival of Slavic religion, and Slavic gods were interpolated in the translations of foreign literary works, such as the "Malalas Chronicle" and the "Alexandreis".