Alexander the Great was born in 356 BCE in Pella, Macedon to King Philip II of Macedon. Philip had Aristotle teach Alexander about Greek culture to prepare him to conquer Greece. Alexander created a vast empire by his early 30s through military conquests and spread Greek culture. He showed signs of megalomania and paranoia later in life. By the 1st century BCE, most of Alexander's empire had fallen under Roman control. The Romans contributed law and applied science through infrastructure but made few scientific advances. Christianity began spreading in the Roman Empire during this period.