Silver Dirham – There is no God but Allah, 8th century
8th century silver dirham minted by the first Umayyad caliph of Spain. The inscriptions read, in part, “There is no god but Allah” and state that the piece—roughly equivalent to a U.S. quarter in size and value—was struck in al-Andalus, as the Arabs called their Spanish domain.
Stewart, Desmond, Early Islam. New York- Time, Inc., 1967.