In the history of nearly a thousand years, Byzantine culture has influenced many cultures in the world with its unique angle, especially Slavic culture. When Slavs entered the Balkans in the 6th century, they were still in the stage of transformation from primitive clan commune to class society. At that time, their cultural development level was very low. By the beginning of the 9th century, the relatively developed Bulgarians in Slavic countries had not yet written their own characters, let alone formed independent cultural characteristics. When they invaded the territory of Byzantine Empire, they came into contact with advanced culture and tried their best to imitate Byzantine political and legal system. They also followed the example of Byzantine emperors and court etiquette, and Byzantine gold, silver and jewels and various luxuries had a subtle influence on Slavic nobles.

In the mid-9th century, the spread of Byzantine culture to Slavic residential areas reached a climax. At that time, Rasdislav, the Archduke of Moravia (reigned from 846 to 870), who was forced to form an alliance with the Byzantine Empire because of the invasion of the Frankish King Charlemagne, wanted to seek military and cultural support and asked Mikhail III to send missionaries to Moravia. Soon, Bulgarian King Bayless I (reigned from 852 to 889) also invited Byzantine Emperor Mikhail III to preach. In 862 AD, Cyril (826-869) and his younger brother meadows were invited to preach, helping Slavs to establish an independent church, creating Cyrillic characters by pinyin of Slavic dialects with Greek letters, and translating the New Testament and ancient Greek works with Cyrillic characters, thus laying the foundation for Slavic literature, and Cyrillic characters also became the origin of Slavic languages. This event is symbolic in the history of Slavic culture development and marks the beginning of Slavic national civilization.

Slavic culture with its own characters has developed rapidly and gradually formed an independent cultural system with distinctive features and rich contents. Due to the introduction of Byzantine culture and Christianity, Rastislav and Berlitz I were regarded as the founders of Slavic culture by later generations. Then, as an independent church actively advocated by local monarchs, it was recognized and supported by the Archbishop of Constantinople and gained legal status. Under the active organization of the church, many monasteries, schools and churches were established in Slavic countries, and a large number of foreign students were sent to study in secular schools in Constantinople.

Serbia later replaced Moravia to control the northwest Balkans, accepted Cyrillic script and eastern Christianity, and Croatia and Dalmatia accepted western Christianity. During the reign of Burleigh's son Simon (892-927), Bulgaria became the center of spreading Byzantine culture. Simon himself received a comprehensive education in Constantinople and was deeply influenced by Byzantine culture. After returning to China, he strongly supported cultural undertakings, took a series of measures to protect artists who were proficient in Byzantine art, and sent students to Constantinople to study Byzantine architecture and rebuild the capital. A large number of Byzantine and ancient Greek books were translated into Slavic. Since then, the ancient oral history of Slavs has been systematically sorted out for the first time. In addition, Simon also imitated Byzantine centralized bureaucracy, re-established government institutions, and established Byzantine tax system accordingly.

Byzantine culture also had a great influence on ancient Russians. Around the end of the 9th century, Novgorod and the Ryurik dynasty in Kiev came into contact with Byzantium and advanced culture. During this period, Byzantine missionaries began to visit Kiev, and Cyrillic characters were also circulated in ancient Russia. Therefore, before Russians formally accepted Christianity, Byzantine Christianity had been quietly changing Russian polytheism belief.