What do you think the relationship developed between the Slavic states and the Byzantine Empire?

In relation to the Slavic states, Byzantium tried to pursue a church policy, which was based on influencing these countries through the church. On the other hand, trade relations often arose between Byzantium and the Slavic states. For example, the merchants of Kievan Rus were constantly trading with the Byzantines. Also, the Slavs often went to war against Byzantium. Although the Byzantine Empire itself very rarely started a war with the Slavs. The exception will be the war with Bulgaria.