1. Philip II, Alexander's father, carried out a series of reforms in military, administrative and financial aspects, weakening the gentry and nobles and strengthening the power of the king. Philip II skillfully used diplomatic and military means to make Macedonia a force and quickly controlled the political situation in Greece.
2. Alexander made full use of the corruption in the Persian Empire and the weak and incompetent situation of King Darius Iii to make a bold attack.
Alexander is one of the great military strategists in the ancient history of the world. His strategic characteristics are: carefully preparing for the war, deeply studying the enemy and ourselves, carrying out the war according to the predetermined plan, resolutely and thoroughly realizing the established plan, annihilating the enemy's effective forces on the battlefield, ensuring Lu Haijun's communication lines and supply bases, and consolidating the victory. The characteristics of command are: surprise, bold invasion, circuitous encirclement, winning more with less, and quick decision. Alexander's military art had a great influence on later western military thought.