Philip came to power in 359 B.C.E. after the Macedonians had just suffered a defeat at the hands of the Illyrians. Macedonia was in political and military turmoil, and Philip immediately set about bringing the people of Macedonia under his control. After exacting revenge on the Illyrians by defeating them in 358 B.C.E., Philip sought to bring all of Upper Macedonia under his control and make them loyal to him. His primary method of creating alliances and strengthening loyalties was through marriage. The most important marriage for Philip was to Olympias, from the royal house of Molossia. By 357 B.C.E., they were married, and she gave birth to Alexander the next year.
Philip had several political and military innovations that helped make Macedonia the power that it was at the time of his assassination in 336 B.C.E. Philip increased the size of the group of Royal Companions, the hetairoi, giving more people positions of power and more of a sense of belonging to the kingdom. He is also credited with beginning the practice of allowing the sons of nobles to recieve education in the court of the king. Here the sons would not only develop a fierce loyalty for the king, but it was also a way for Philip to, in a sense, hold the children hostage to keep their parents from interfering with his authority.
Philip's military zenith was at the battle at Chaeronea in August of 338 B.C.E. Philip's army was greatly outnumbered by the Athenian and Theban forces, yet his phalanxes overwhelmed the Athenians and Thebans. Athens and Thebes were forced to become subjects of Philip and Macedonia, leaving Sparta as the only Greek state not under Macedonian control.
At the Council at Corinth the next year, Philip outlined his system for ruling the Greek states. He gave freedom and autonomy to all the political parties in each state, yet established a network of bureaucracies that would be stable and loyal to Philip. Then, with the support of all Greece, Philip declared war on Persia to retaliate for the Persian invasion of Greece several generations before. In the spring of 336 B.C.E., Philip sent Attalus and Parmenion with 10,000 troops over into Asia Minor to begin liberating Greek cities along the coast. Just before Philip himself was to travel to Asia to begin the conquest, he was assassinated.
According to the ancient source Diodorus, Philip was hosting a massive banquet as a going away party before he left for Asia. Leading the procession into the theater on the second day, were thirteen statues, twelve of the Olympian gods and one of Philip. Philip wanted his march into the theater to be triumphant, and so he asked his bodyguards to stand back and out of the way to show to his people that he had nothing to fear. At that very moment, however, a man named Pausanias rushed forward from the crowd and stuck a dagger in Philip's chest. During his escape, Pausanias tripped and fell and was killed on the spot.
Pausanias had sought revenge from Philip because apparently he, the king, and another man named Pausanias were involved in a love triangle. The first Pausanias was a handsome bodyguard of Philip's, whom Philip enjoyed very much. Soon the second Pausanias seemed to replace the first as a favorite of the king's. The first Pausanias called the second one a whore, and, with his pride wounded, the second Pausanias gave his life up for the king by taking blows meant for Philip in a battle with the Illyrians.
The first Pausanias now felt slighted because he believed that Philip still liked the dead Pausanias. To ease his pain, Attalus, a close friend of the king and leader of the upcoming invasion of Asia, got Pausanias drunk and then let several stable boys rape him. Philip liked Attalus too much to punish him, and instead gave Pausanias a promotion to a higher position as bodyguard to placate him. Doubly slighted, Pausanias plotted to kill Philip in the manner mentioned above.