Do you look forward to the day when you'll be a grown-up? When you're 16, you can get your driver's license. When you're 18, you'll graduate from high school and vote in your first election. By age 20, you'll probably be in college or working your first job.

That's a lot to look forward to, isn't it? Of course, by ancient standards, those accomplishments might not seem all that impressive. It's not like you'll take command of a military unit when you turn 18 or become king of a large empire by the time you turn 20. But that's what Alexander the Great did. Maybe that's why he has "the Great" attached to his name!

Born in the Pella region of Macedonia (modern-day Greece) in 356 B.C., Alexander the Great was the son of King Philip II of Macedon and Queen Olympia. As a boy, Alexander enjoyed the benefits of royalty, including an education provided by famous philosopher Aristotle.

At the age of 17, Alexander joined the military and went on his first expedition. He rose to prominence quickly, taking command of the Companion Cavalry only a year later when he was just 18 years old.

As a young cavalry commander, he helped his father defeat the Athenian and Theban armies, thereby uniting the Greek city-states (with the exception of Sparta) and forming the Corinthian League. His relationship with his father fell apart when his father ousted his mother, Olympia, and married Cleopatra.

Alexander fled with his mother, and they stayed with her family. In 336 B.C., Alexander's father was murdered. With the help of the military and his mother, Alexander returned and became king of Macedonia at the young age of 20. He ruled as the Macedonian king from 336 to 323 B.C.

Under Alexander's leadership, Macedonia flourished. He used his military experience and political savviness to further unite the Greek city-states. He also convinced them to let him serve as the leader of the Corinthian League.

When necessary, he used the military to destroy adversaries threatening to leave the alliance he had built. In this way, he consolidated his power and hold over Macedonia and the rest of the Greek city-states.

Eventually, Alexander set his sights on Asia to the east. Despite being outnumbered, Alexander used brilliant military strategies to conquer King Darius III. He proclaimed himself king of Persia in 333 B.C.

His next target was Egypt, which fell easily to Alexander. He created the city of Alexandria in 331 B.C., and it soon became a thriving center of trade and Greek culture. Later that year, he defeated the remainder of the Persian army, proclaiming himself "King of Babylon, King of Asia, King of the Four Quarters of the World."

Alexander and his army continued to conquer more areas to the east, including forays into Iran and India. The many Macedonian colonies he established help to spread Greek culture far beyond its borders into Asia.

If he had lived longer, there's no telling how far Alexander would've extended his empire. Historians believe that he was contemplating campaigns against Carthage and Rome when he died of malaria in Babylon (modern-day Iraq) in 323 B.C. at the young age of 32.