I found "Byzantium The Apogee" to be a wonderful book, breathing life into a fascinating yet neglected area of history. I thought that J J Norwich's witty and perceptive commentary lifted a veil on the passions, ambitions and the (sometimes bizzare) obsessions of the procession of emperors - along with their numerous consorts, mistresses, eunuchs, officials, generals, rivals and enemies. The result is an epic story - sometimes high drama, sometimes tragedy and at other times breathtaking farce.
Please take my advice and read the three separate volumes: although there is a single volume edition, it is abridged - you really don't want to miss anything from this fascinating saga.