This lecture series provides incredible detail into the world of Byzantium and its relationships to other civilizations over the millennium of its existence. This is a time period during the middle ages that I, and many I know, lack much knowledge.
The only complaint I have is that the information comes too fast. It really is designed as a lecture, where you can sit and take notes. Not having that opportunity, I suspect I will not retain much, but the lecture would be worth a second hearing.