The incredible story of Alexander the Great and his conquest of the known world is brought to life with animated maps, images from Osprey Publishing and Total War game footage. In Part 1, we look at the background: Persia's invasion of Greece in 480 BC, the rise of Macedonia under King Philip II, and the formation of the Hellenic League. Following Philip's assassination, his 20 year old son Alexander inherited the kingdom and a formidable army. In 334 BC he used this army to launch a invasion of the Persian Empire, winning a crucial victory at the River Granicus.