Long ago, there were two big groups of people called the Rus and the Byzantines. They were living far away from each other and didn't know each other very well.
One day, the Rus people decided they wanted to trade with the Byzantines. But the Byzantine people were a little hesitant because they didn't know the Rus people and weren't sure if they could trust them.
The Rus people tried to show the Byzantine people that they were friendly and wanted to trade. But unfortunately, something went wrong and the Byzantines got afraid that the Rus were going to try and attack them.
Because the Byzantines were afraid, they decided to fight against the Rus people. The Rus people were very strong and brave, but the Byzantine people were really good at fighting too.
The war was very hard and lasted a really long time. In the end, both groups were really tired, and they finally decided to stop fighting. They realized it was better to be friends and trade with each other instead of fighting.
So they made a treaty, which is like a promise, to be friends and trade with each other from then on. And that's how the Rus and Byzantine people became friends and started working together to trade and be peaceful.