Lord Norwich knows how to write for a popular audience: Although he denies any claim to academic rigor, one must note that after two well-received books on the Normans in Sicily, studies of Mount Athos and Venice, and the first volume of this projected trilogy, he is well-acquainted with the primary sources and the scholarly studies of Byzantine history.

The Byzantine Empire was under great pressure in 800, the year Charlemagne was crowned in Rome as (Holy) Roman Emperor. The empress, Irene, faced a dangerous rival in the Bulgarian monarch and the Arab Caliph, and her unhappy subjects hated her reverence for icons. Moreover, as a woman, she could not be envisioned as a military leader no matter how brutally she treated her enemies and even her own family. When Nicephorus came to the throne in 802, he chose to reduce the number of enemies by accepting Charlemagne as an equal ruler, but his subsequent successes against the Bulgars ended in military disaster in 811.

The following decades were filled with invasions, plots, and coups. These were nevertheless great years for the Greek Church: The Patriarch Photius warded off the threatened papal domination, while the missionaries Cyril and Methodius spread Christianity into the Slavic lands to the north. When Boris II (“the Bulgar-killer”) became emperor in 976, the tide turned; the flawless organization of Boris’ army and his skillful diplomacy made Byzantium once again the dominant power of...

(The entire section is 404 words.)