381-336 B.C.

Macedonian general who became king of Macedon and reorganized its army. Philip developed the deep phalanx, introduced the sarissa (18-foot-long, or 5.5-meter-long, spear), and increased the mobility of his army by reducing its baggage. He also reformed battlefield tactics by having cavalry units fight in close concert with infantry units. As a result, Philip subjugated Illyria, Thrace, and was made the supreme commander of Greece. He was assassinated before his planned invasion of Persia.