Alejandro Magno, also known as Alexander the Great, was a king of the ancient Greek kingdom of Macedonia and one of history's most successful military commanders. Born in 356 BC, he became king at the age of 20 after the assassination of his father, Philip II. He is best known for creating one of the largest empires in the ancient world, stretching from Greece to northwest India. Throughout his conquests, Alejandro Magno spread Greek culture and influence, a period known as the Hellenistic Era. He is famous for battles such as the Battle of Gaugamela and the founding of cities like Alexandria in Egypt. His legacy continues to be studied in military strategy and leadership.