In 1453 the forces of the Ottoman Empire finally succeeded in capturing the city of Constantinople. The Ottoman victory meant that the last vestige of the once powerful Roman Empire was no longer open to free trade by European governments. At a time when the world lacked an effective form of artificial refrigeration, spices such as pepper, cinnamon, nutmeg, clove, ginger, turmeric, and anise were all in great demand throughout Europe to preserve the flavor of perishable food, and some of these spices were thought to be useful in dealing with the effects of a variety of diseases.