The ducat /ˈdʌkət/ was a gold or silver coin used as a trade coin in Europe from the later medieval centuries until as late as the 20th century. Many types of ducats had various metallic content and purchasing power throughout that period. The gold ducat of Venice gained wide international acceptance, like the medieval Byzantine hyperpyron and the Florentine florin, or the modern British pound sterling and the United States dollar.
Nederland Gouden Dukaat 1724
Saint Mark standing giving gonfalone to the kneeling doge. S(anctus) M(arcus) VENET(I) DVX MICAEL STEN
Christ standing among stars in oval frame. SIT T[ibi] XPE (Christe) DAT[us] Q[uem] T
REGIS ISTE DVCAT
Ducat of Venice Venezia Ducato 1400
Austrian gold ducats depicting Kaiser Franz-Josef, c. 1910
Silver ducat of Roger II of Sicily 1140 AD