Everyone knows the great conquest of Alexander the Great and his great achievements. He defeated Darius III and reached the river banks of the Indus. But all of this could not be achieved if his father, Philip II, didn’t set the stage for these victories. Philip II was born around 382 BC as the youngest son of Amyntas III. In his youth he witnessed the struggle of the Macedonian Kingdom with the invasions of the Illyrians on the north and the political intrigue of Thebes. Philip spent three years as a hostage in Thebes around 367, which was a leading power at this period. His brother Perdiccas III manage to get him released.
The beginning of Philip’s reign
After the short reign of Alecander II and Perdiccas in 359 BC Philip took the throne of the Macedonian Kingdom. He realized the weaknesses of the army and knew he could not go against his opponents. He bought his dangerous neighbors, gaining time for military preparations. The famous Secret Band and the tactical abilities of their commanders Epaminondas and Pelopidas served as a great experience for Philip. He used this experience to reorganize the Macedonian army, making professional soldiers. Also, he started developing siege weapons, mostly towers and catapults. One of the most important military reforms was the restructure of the phalanx. He changed the hoplite spear with a sarissa, a 5-6 meter (18 to 20 feet) long pike. A new type of helmet and a new type of shield were designed, and each soldier possessed a small double-edge sword for close-in-hand fight. In 358 BC he invaded Paeonia, defeated the Illyrians and married Olympias the next year, Molossian princess of Epirus and the mother of Alexander the Great. This stabilized the west border so Philip could achieve other plans. He captured Amphipolis from Athens, which give access to Thrace. In 356 he invaded western Thrace and captured Crenides, a newly founded city for mining silver and gold in Mount Pangaeum.
Macedonian-Greek relationship
In 356 the Phocians sized the city of Delphi, home of the famous oracle, provoking the Third Sacred war. Athens and Sparta joined the war on the side of the Phocians against the Thessalian League. The League asked Philip for help. They crushed the Phocian commander Onomarchus at the Battle of Crocus Field in 352 BC. He was made an archon of the Thessalian League, which was strange since Philip was a foreigner to the Greeks. In 354 BC he captured the city of Methone, and in 348 BC Olynthus and Chalcidice. At this period of wars, he lost an eye, broke his shoulder and crippled his leg. In 346 Philip led a campaign in Thrace, challenging Athens control of the sea route of the main source of imported grain. Anyhow, a peace was signed the same year with Athens. He used the votes of the Thessalians to control the Delphic Amphictyony- an association of neighboring states. The next period from 346 to 343 BC he took parts of Greece without war, by winning and buying politicians of the smaller states. This made him enemies, one of which was Demosthenes, a great orator from Athens. He constantly railed against Philip in a series of speeches called “The Philippics”. Demosthenes saw Philip as a treat to Athens’ freedom and existence, convincing Athens and all the other Greeks that the “barbarian” Philip was a threat to all of Greece. Meanwhile Philip grew even stronger. He tightened his grip in Illyria and Thessaly, and in 342 BC began another campaign in Thrace, annexing almost all of it as a province in just two years. Afterwards he battled the Scythians on the southern bank of the Danube Delta. As a result of the campaign in Thrace, two of his allies, Perinthus and Byzantium reconsidered their positions. Philip took under siege some cities, but in 340 BC Athens declared war on him, so he had to give up and retreat. A big impact on the decision of Athens to declare war had Demosthenes. 
The Battle of Chaeronea and the end of Philips reign
In 338 BC the Battle of Chaeronea was a turning point in history. Athenians, Thebans and a small number of allies with 10 000 infantry and 600 cavalry from Athens and 12 000 infantry and 800 cavalry from the Thebes, confronted Philip who had 30 000 infantry and 3 000 cavalry. The left wing of the Macedonian army, Philip left to his son Alexander who showed courage and military skills. The Athenians charged first at Philip, but they were crushed. The allies, who were in the middle of the Greek formation fled immediately after this and Alexander, managed to surround Thebes’ Secret Band, crushing them completely. Demosthenes was a part of this battle, and he fled together with the Athenians.
After the defeat, peace was established with the Corinth treaty. Everyone, except Sparta was part of this treaty. Thebes had to admit a Macedonian garrison and a pro-Macedonian government. Athens was forced into an alliance, but was not invaded. The reason for this can be found in Philip’s plans to invade Persia. He needed the Persians to be denied the use of the Aegean, and for this he needed the Athenian navy. Macedonia established full hegemony over Greece, and Philip as a hegemon. Some modern historians claim that the settlement with Greece is Philip’s culmination, but this cannot be true since he was not a Greek politician nor even a Greek, but king of Macedonia. On top of that, the only thing he needed from the Greeks for them not rise against him, if he was to achieve his plans of conquest in Persia.
After the Corinth treaty, Philip started the preparations for crossing in to Asia. While the preparations were still in motion, at the wedding of his daughter Cleopatra with Alexander of Epirus, Philip was assassinated by Pausanias, a Macedonian noble. He was killed on the spot. Suspicion fell on Olympias and Alexander, but Aristotle did not believe in it, as he stated in his Politics. The throne was succeeded by Alexander III of Macedon, who will latter reach the river Banks of the Indus river, mostly because of the successes and politics of his father.