I want to know the answer to the following question:
When did the relations between the Rus and Byzantines start to become more complicated?
All the background I'm provided with is that "Byzantine sources do not mention the attack, but a pair of treaties in 907 and 911 set forth a trade agreement with the Rus', the terms suggesting pressure on the Byzantines, who granted the Rus' quarters and supplies for their merchants and tax-free trading privileges in Constantinople.". Is that enough to answer the question?
Answer: no