[SunkenCiv]

It wouldn’t surprise me. There was seagoing trade from Constantinople to a lot of nooks and crannies in Britain throughout the so-called Dark Ages, and this was much later, after the Varangians had been working for the Byzantines for centuries. The Viking mercenaries helped run the saracens out of Sicily, and the Normans later established a short-lived kingdom there.

[colorado tanker]

I think a Turkish presence would be unlikely. The Seljuks at the time were just beginning to move into Fatamid territory in the Middle East and began a war with the Byzantines in 1068 that culminated in the Battle of Manzikert, only after which did they control a significant chunk of Anatolia. Even then, they still did not control Constantinople.

They were pretty busy with their own wars at the time of the Norman Invasion.