One of the first podcast I ever listened to was "12 Byzantine Emperors" by Lars Brownsworth. The podcast tells the history of the reign of 12 different emperors (and empress) of the Eastern Roman empire, starting with Diocletian and ending with Constantine XVI. This podcast series is, without a doubt, one of the best history series out there today. Fortuitously, I stumbled upon this lecture series by Brownsworth himself on Youtube. Very interesting.