

Alexander endeavored to reach the "ends of the world and the Great Outer Sea" and invaded India in 326 BC, achieving an important victory over Porus, an ancient Indian king of present-day Punjab, at the Battle of the Hydaspes. After the fall of Persia, the Macedonian Empire held a vast swath of territory between the Adriatic Sea and the Indus River. Following his conquest of Asia Minor, Alexander broke the power of Achaemenid Persia in a series of decisive battles, including those at Issus and Gaugamela he subsequently overthrew Darius III and conquered the Achaemenid Empire in its entirety. In 334 BC, he invaded the Achaemenid Persian Empire and began a series of campaigns that lasted for 10 years. Alexander then led the League of Corinth, and used his authority to launch the pan-Hellenic project envisaged by his father, assuming leadership over all Greeks in their conquest of Persia. In 335 BC, shortly after his assumption of kingship over Macedon, he campaigned in the Balkans and reasserted control over Thrace and Illyria before marching on the city of Thebes, which was subsequently destroyed in battle. Until the age of 16, Alexander was tutored by Aristotle.

He was undefeated in battle and is widely considered to be one of history's greatest and most successful military commanders.

By the age of 30, he had created one of the largest empires in history, stretching from Greece to northwestern India. He succeeded his father Philip II to the throne in 336 BC at the age of 20, and spent most of his ruling years conducting a lengthy military campaign throughout Western Asia and Egypt. Alexander III of Macedon ( Ancient Greek: Ἀλέξανδρος, romanized: Alexandros 20/21 July 356 BC – 10/11 June 323 BC), commonly known as Alexander the Great, was a king of the ancient Greek kingdom of Macedon.
