The army of the Ancient kingdom of Macedonia was among the greatest military forces of the ancient world. It became formidable under King Philip II of Macedon and his son, Alexander the Great.

The latest innovations in weapons and tactics, along with unique combination of military elements introduced by Philip II, came together into the army that won an intercontinental empire. By introducing military service as a full-time occupation, Philip was able to drill his men regularly, ensuring unity and cohesion in his ranks. In a remarkably short time, this led to one of the finest military machines that Asia or Greece had ever seen.

Tactical innovations included adaptations of the latest tactics applied to the traditional Greek phalanx by men such as Epaminondas of Thebes (who twice defeated the Spartans), as well as coordinated attacks (early combined arms tactics) with the various arms of his army — the phalanx, cavalry, missile troops, and (under Alexander III) siege engines. A novel weapon was introduced, the sarissa, a type of counter-weighted (like all Greek spears) pike, which gave its wielder many advantages both offensively and defensively. For the first time in Greek warfare cavalry became a decisive arm in battle.