rowns are the quintessential symbol of royal sovereignty. They have been used on coins since the 4th century B.C. Crowns have taken many forms over time—Greek monarchs of the Hellenistic age preferred simple diadems consisting of a cloth ribbon, the Parthians developed an elaborate, jewel–encrusted crown which was further elaborated by the Sassanian Persians into distinctive crowns for each of their rulers, while the Romans used crowns to symbolize divinity or to identify personifications of cities. By the 4th century A.D., Roman Emperors were depicted wearing diadems, which, under the Byzantines, became increasingly elaborate crowns. Medieval kingdoms adopted the idea of the crown from the Byzantines and began to depict crowns on coins as they got larger and craftsmanship improved.Crowns have remained on coins ever since, often used to explicitly highlight the autocratic nature of the issuing authority as in the gold coin of Carol II of Romania below.