From there, overland routes led to the Mediterranean coasts. From the 8th until the 15th century, maritime republics (Republic of Venice, Republic of Pisa, Republic of Genoa, Duchy of Amalfi, Duchy of Gaeta, Republic of Ancona and Republic of Ragusa) held a monopoly on European trade with the Middle East. The silk and spice trade, involving spices, incense, herbs, drugs and opium, made these Mediterranean city-states rich. Spices were among the most expensive and in-demand products of the Middle Ages, used in medicine as well as in the kitchen. They were all imported from Asia and Africa. Venetian and other navigators of maritime republics then distributed the goods through Europe.