The Byzantine Empire, with its thousand-year presence in world history, is surrounded by admiration for the wealth and radiance of its culture. However, equally remarkable is how it survived for so many centuries in a strategically bleak environment, constantly repelling attacks from enemies who usually had the advantage of numbers, without having either inexhaustible material and human resources or strategic depth.

Its strategic problem was that with limited means, it had to achieve much. The Byzantines knew they could not conquer their enemies, as their predecessors the Romans did, through the use of brute force. Their excellently trained and highly professional, but costly, army was always outnumbered. Nor did it make sense to exterminate one enemy, as another, equally or more dangerous, would immediately take their place.

They realized they had to resort to diplomacy, impose themselves with the gentle power of their cultural, religious, and political influence, buy off enemies with "grants," and turn one enemy against another with beneficial incentives. Their success depended on healthy finances, the most advanced tax system of the time, effective bureaucracy, and the continuous collection and processing of information about their neighbors, be they friends or foes.

The Byzantine army learned to adapt to every strategic situation, not hesitating to copy successful methods from the enemy. It had many types of troops cooperating with each other, a plethora of weapons, and a large repertoire of tactics for every occasion. It was reluctant to engage in battle when overwhelming superiority and certainty of victory were not assured, because it knew that winning a battle was not enough when the goal was to win the war.

The pinnacle of Byzantine strategic understanding is the recording of fundamental principles of action in a series of manuals that allow us to reconstruct every aspect of life in the Byzantine army, from the training stage to the moment of victorious conflict. Based on the fruits of the most modern research in Byzantine studies, the author analyzes original sources and extracts from them a diagram of the Byzantine "operational code," outlining the "Byzantine way of war," demonstrating the reasons why the Eastern Roman Empire, i.e., the Byzantine Empire, survived a full eight centuries longer than its counterpart in the West.