Alexander the Great was a king of the ancient Greek kingdom of Macedon in the fourth century BC. He is best known for his vast empire, which covered areas from Greece to Egypt and as far east as India, making him one of the most successful military leaders in history. Alexander was tutored by the philosopher Aristotle during his childhood and began his reign at the young age of 20 after his father, Philip II was assassinated. Noted for his tactical genius, ambition, and cultural influence, Alexander's conquests spread Greek culture throughout the known world, an era known as the Hellenistic period, and his early death at the age of 32 added to his legendary status.