Jupiter, the king of the Roman gods, is one of mythology's outstanding and most powerful figures. Interestingly enough, the planet which is named after him is the largest in the entire Solar System -- a lasting reminder of Jupiter's greatness. Jupiter was important in a time when Romans were worshipping Greek-like gods and goddesses, immortal and tremendously enhanced versions of men and women; for a brief summary of Roman religion, consult our timeline. Throughout, you will find several words derived almost directly from Latin, the supposedly "dead" language that provides the basis for over half of all English words -- incredible!
Jupiter was the king of the Roman gods, the Roman equivalent of the Greeks' god Zeus. In the beginning, he was Saturn's son (sun?) and king of the sky and heavens, worshipped as the god of thunder and lightning, but later he overthrew his father and became chief of the Roman gods. To the people of Rome, Jupiter served two important functions:
Jupiter was, in the Greek tradition, the Romans' supreme god and he was given many of Zeus's same traits in literature. He ruled over the gods, convening (convenire = to convene) conferences in his large, lavish palace, which was built by Vulcan, the Roman god of fire.
Using lightning bolts to kill sometimes three and four at a time, Jupiter was always asserting his authority over other gods and over the low mortals. In one respect in particular, Jupiter was of great importance to astronomy, supposedly putting mythical characters into the sky after their deaths. We still remember these myths today, though they are told as many different accounts, and Jupiter's mythological work shows up everywhere in astronomy -- every time we speak of a constellation (stella = star) or planet!