Byzantium was one of the greatest empires that ever existed. It reigned over extensive regions around the Mediterranean and in Eastern Europe from its founding by Constantine in 324 to the fall of Constantinople in 1453. During this period, its emperors had not only secular powers but also religious, dominating the Orthodox church that spread into Slavic lands. However, internal divisions, rivalry with the West, and the relentless battle against invaders, including the Ottomans, would eventually weaken the Byzantine Empire, and although it disappeared half a millennia ago, its influences can still be seen today in Eastern Orthodoxy and Byzantine art and archaeology.

The A to Z of Byzantium covers an impressively long period of over a thousand years, balancing the high points as it expanded and flourished and the low points when it was pushed back. The major events are first marked in the chronology and then expanded upon in the introduction. What actually transpired can then be seen in greater detail through several hundred cross-referenced dictionary entries describing important persons, institutions, events, and significant aspects of the economy, society, culture, religion, and warfare. A bibliography of supplementary material concludes the book.