Tactica

The Tactica is a military handbook attributed to the Byzantine emperor Leo VI the Wise, who reigned from 886 to 912 CE. This work drew heavily on earlier military treatises, particularly the Taktikē theōria by Aelianus, a Greek writer from the 2nd century AD. Aelianus's manual focused on arming, organizing, deploying, and maneuvering armies, primarily based on Hellenistic warfare practices.12

The Tactica of Leo VI, like Aelianus's work, dealt with formations, weapons, and methods of combat. It influenced Byzantine military thought and later military practices in both the Muslim world and post-15th-century Europe. The term "tactics" itself originates from the Greek word taxis, meaning order or arrangement, and tactica, the art of drawing up soldiers for battle.12