Answer:
The point of view is in the third person.
Step-by-step explanation:
The third person point of view can be seen in texts where the narrator does not participate in the events he is narrating. It shows what other people have done, as an observer who is retelling someone's facts and events. As we can see, Byzantine knight does not participate in the events he is talking about, he only tells what he knows, which is the strongest indication of narration with a third person point of view.
In addition, the third-person point of view uses pronouns (or equivalent words) in third persons, such as "it", "he" and "they", which we can see in this letter.