That is some video you posted in there even if the link didn't pick it up directly. A bit strong in the use of selected imagery about the people of the Jewish Faith.
And CyrilVladisla, thanks for your video!
I love to check out information on the Eastern Roman empire and, since a time I can't remember, my favorite book on the subject is The Alexiad. Especially the versions that have a glossary of terms or foot notes to describe the titles used in the Empire for officials that are different than their Latin/Western Empire counterparts.