In the story, the visiting Norman palmers (pilgrims to the Holy Land, not necessarily crusaders) aren’t terribly welcome by the new emperor. One of the reasons why is that the Normans, after taking Sicily, inflicted heavy damage on the Byzantine army and nearly destroyed the ranks of the Varangian Guard during the Battle of Dyrrhachium in 1081. No mention of this battle is in the current draft of the story. However, I think it gives me a good piece of history to incorporate into the sequel(s) when I get there.
Some emperors may have gotten along with the expanding Normans, but most didn’t. So I stand by my vagary in that the book takes place “sometime” in the 11th Century.