[xiii] Spanish coins of the sixteenth century were the following:
 

Ducat = 375 maravedís
Escudo = 350 maravedís; 400 (after 1566)
Real = 34 maravedís
Cuarto = 4 maravedís
Blanca = 1/2 maravedí
 

The maravedí was the smallest unit of account in the Castilian monetary system; its approximate value was one-sixth of a cent.