A diadem is a type of crown or headband worn as a symbol of royalty or high status. Unlike the heavy golden crowns you might picture on kings and queens, a diadem is usually simpler and lighter: a jeweled band, often made of gold or silver, that circles the head.

In ancient Greece and Rome, victorious athletes and military leaders wore diadems made of laurel leaves. Later, emperors and empresses wore metal diadems decorated with precious gems to show their authority. When you read about ancient royalty, a diadem is often what they're actually wearing rather than the big, pointed crowns you see in cartoons.

Today, the word sometimes describes fancy tiaras worn at formal events, though technically a tiara is taller and more elaborate than a traditional diadem. In stories and historical accounts, a diadem represents power and legitimacy: putting on the diadem meant claiming the throne, and removing it meant giving up power. The simple circle of a diadem carried enormous meaning because everyone recognized what it symbolized.