Alexander III of Macedon, known as Alexander the Great, was born on 20 July 356 BCE in Pella, the capital of Macedon. He was the son of King Philip II and Olympias. Alexander was tutored by Aristotle until the age of 16, where he learned various subjects, including philosophy and military tactics. At 20, he ascended to the throne after the assassination of his father in 336 BCE. His early reign involved quelling revolts in Greece, notably destroying Thebes to assert his power.In 334 BCE, Alexander launched a campaign against the Achaemenid Persian Empire, beginning with the invasion of Asia Minor. He achieved significant victories at the Battles of Granicus, Issus, and Gaugamela, ultimately overthrowing Darius III and conquering the Persian Empire. By 330 BCE, he had established control over vast territories, including Egypt, where he was crowned pharaoh and founded the city of Alexandria. His military campaigns extended into Central Asia and the Indian subcontinent, where he faced King Porus at the Battle of the Hydaspes in 326 BCE, emerging victorious.Despite his successes, Alexander's troops mutinied at the Beas River, refusing to march further into India. He then turned back, leading his army through the Gedrosian Desert, suffering heavy losses. Upon returning to Babylon in 324 BCE, he faced challenges from his satraps and adopted some Persian customs, which alienated many Macedonians. His close companion, Hephaestion, died in 324 BCE, deeply affecting Alexander's mental state.Alexander died on 10 or 11 June 323 BCE in Babylon at the age of 32. The cause of his death remains debated, with theories ranging from natural causes to poisoning. Following his death, his empire fragmented due to power struggles among his generals, known as the Diadochi. Alexander's legacy includes the spread of Hellenistic culture, the founding of numerous cities, and the establishment of Greek as a lingua franca in the regions he conquered. His military tactics and strategies continue to be studied in military academies worldwide.