Heraclius reformed the Byzantine military in the 7th century, creating the theme system, which divided the empire into military districts.

The primary weapon of the Byzantine infantry was the spear, which was used for both thrusting and throwing.

Heraclius defeated the Persians and Avars in the 7th century, securing the eastern and western borders of the Byzantine Empire.

Leo III defeated the Arabs at the Battle of Akroinon in 740 and the Bulgarians at the Battle of Marcellae in 792.

The Byzantine Navy was the naval force of the Byzantine Empire.

Basil I defeated the Normans at the Battle of Thessalonica in 885.

The Strategikon was a military manual written by Emperor Maurice in the 6th century.

Alexios I Komnenos defeated the Seljuk Turks at the Battle of Dorylaeum in 1097.

Cataphracts were heavily armored cavalry units that formed the elite of the Byzantine army.

Manuel I Komnenos defeated the Crusaders at the Battle of Myriokephalon in 1176.

The Varangian Guard was a unit of foreign mercenaries that served as the personal bodyguard of the Byzantine emperor.

John VI Kantakouzenos defeated the Ottomans at the Battle of Pelekanon in 1329.

Peltasts were light infantry units that were used for skirmishing and missile warfare.

Stephen Dushan was a Serbian emperor who defeated the Byzantines at the Battle of Velbu?d in 1330.