u/Beltharean mentioned that some of the Saxon nobility disposed of by the Normans went on to become mercenaries, notably in the Byzantine Empire. At the risk of being too vague, can someone explain how this occurred and what impact it had?

by ColbyStein

Considering the Romans used to control parts of Britain, a long long time before these events, did the Byzantines take particular interest in the origin and history of these foreign mercenaries? Was there any significant informational or cultural exchange?