a foreign coin, either of gold or silver, struck in the dominions of a duke. The ducat was first coined by Longinus, governor of Italy, who revolted against the emperor Justin the Younger, and made himself duke of Ravenna, calling himself Exarcha, that is without lord or ruler; and he struck pieces of money of very pure gold with his own stamp, which, as Procopius relates, were called ducati, ducats. According to Du Cange, ducats were coined by Roger, king of Sicily, in the year 1240. The Venetian ducat was first struck by John Dandolo in 1280, and inscribed with this legend:

SIT TIBI, CHRISTE, DATUS, QUAM TU REGIS ISTE DUCATUS.