Star (heraldry) in the context of Coat of arms of the Washington family

The conjoined representation of a star and a crescent is used in various historical contexts, including as a prominent symbol of the Ottoman Empire, and in contemporary times, as a national symbol by some countries, and by some Muslims as a symbol of Islam, while other Muslims reject it as an Islamic symbol. It was developed in the Greek colony of Byzantium ca. 300 BC, though it became more widely used as the royal emblem of Pontic king Mithridates VI Eupator after he incorporated Byzantium into his kingdom for a short period. During the 5th century, it was present in coins minted by the Persian Sassanian Empire; the symbol was represented in the coins minted across the empire throughout the Middle East for more than 400 years from the 3rd century until the fall of the Sassanians after the Muslim conquest of Persia in the 7th century. The conquering Muslim rulers kept the symbol in their coinage during the early years of the caliphate, as the coins were exact replicas of the Sassanian coins.

Both elements of the symbol have a long history in the iconography of the Ancient Near East as representing either the Sun and Moon or the Moon and Venus (Morning Star) (or their divine personifications). It has been suggested that the crescent actually represents Venus, or the Sun during an eclipse. Coins with star and crescent symbols represented separately have a longer history, with possible ties to older Mesopotamian iconography. The star, or Sun, is often shown within the arc of the crescent (also called star in crescent, or star within crescent, for disambiguation of depictions of a star and a crescent side by side). In numismatics in particular, the term pellet within crescent is used in cases where the star is simplified to a single dot.