Just in case you're wondering, my study of Byzantium, aka Constantinople, now Istanbul*, came about as a direct result of my reading about Vikings. In the late 10th century, the ever rowdy Danes sailed their longboats down into the Mediterranean and attacked Constantinople. Eventually the Vikings and the Romans worked things out and the Vikings ended up as bodyguards and soldiers for the emperors of the Byzantium Empire.
Now being me, whenever I begin studying a culture, I'm always trying to build a mental picture of the place in my mind. What did the buildings look like? What kind of clothes did the people wear? What did they eat? What kind of weapons did they use?
Thing about the Byzantium Empire is, its citizens considered it part and parcel of the Roman Empire. They didn't differentiate between themselves and the Toga boys over in Italy. They referred to themselves as Romans. That's helpful because I already know a lot about the Roman Empire. Still given distance, cultural differences, climate, and what have you, the 'look' of Byzantium isn't just Rome warmed over. Fortunately there are many surviving works of art from the 10th and 11th centuries so I can get a pretty good idea of how things looked. The Oxford History of Byzantium has been darn useful for that.
(*And for some reason whenever I mention Constantinople, everyone starts singing the song "Istanbul Not Constantinople" and asks if I've heard of it. Yes, for pity's sake. They Might Be Giants did the cover all of you remember, though the song is actually of tin pan alley vintage. It was on Tiny Toons Adventures. I know. Thanks. And for that matter, the band got their name from the 1971 film "They Might Be Giants" starring Geroge C. Scott as a man who thinks he's Sherlock Holmes if you want some more useless trivia.)