Having finally been robbed of its Black Sea commerce by the Turks, and later defeated by the superior power of its old enemy the Venetians in other parts of the Mediterranean, the Genoese turned their attention in another direction, hoping thereby to retrieve their fortunes. There were among Genoese sailors some who were acquainted with the globular form of the earth, having acquired this knowledge from the Mohammedan astronomers, and these men originated the attempt to reach India by sailing to the west. Greatest and best among them, seeking the welfare of his city and hoping that the riches of India might thus be secured, was Christopher Columbus, the son of a wool comber. He had studied the ordinary branches of arithmetic, drawing and painting, and is said to have acquired a singularly beautiful handwriting. After attending the university for a short time, he went to sea when fourteen years of age, and for many years was engaged in the Syrian trade and in that of other ports, later turning his attention to the construction of charts for sale, and the deeper study of geography and navigation.

The result of Columbus' discovery was to draw the attention of Europe to the westward and dispel the mystery of the open sea. Migration set in towards the western coast of Europe, and the sea route to India diverted commerce in other channels. Genoa became subject to Milan, and although it again grew prosperous, it never regained its former commercial importance.

Only second in importance to the republics of Venice and Genoa was the city of Pisa, situated in a plain between the Appe-nines on the east and the Tuscan Sea on the west. The founding of the city, like that of Genoa, dates back to the Roman Empire, and like all other Italian cities, Pisa suffered from the barbarian conquest; but like them, too, she secured her independence, set up a republican form of government, and rapidly sprang forward to a foremost place among the maritime states of Italy. In the eleventh century Pisa acquired the islands of Sardinia, Corsica and Elba, besides adding many important districts along the coast to its territory, with all of which it carried on a prosperous commerce. The crusades poured fresh wealth into the lap of Pisa, and in return for its help in transporting the armament to Palestine, Pisa was given extensive privileges and became one of the channels through which the produce of the east flowed in upon the ruder nations of western Europe. Pisa reached the zenith of its power at about the end of the eleventh century. Its prosperity was marked by public edifices which stand as monuments to Pisan greatness to this day. Pisa was the first Italian city which took pride in architecture, and its leaning tower and cathedral are examples of skill and beauty. It was in this cathedral that the illustrious philosopher, Galileo, watched the swinging of the chandelier, and observing that its vibrations, large and small, were made in equal times, "left the house of God, his prayers unsaid, but the pendulum clock invented." The Pisans are also credited with being the first to codify and promulgate a system of maritime law suited to the extensive Mediterranean commerce, defining the rights of neutral and belligerent vessels, and thus laying the foundation for a portion, at least, of the international law of modern times. In the course of time Pisa succumbed to the wars and competition of rival cities. Genoa was its most bitter enemy, and in one fatal battle off the Island of Meloria, in 1284, the entire Pisan navy was destroyed. Torn by dissensions, and stripped of her commerce and colonies, Pisa was finally sold in 1406 to Florence for 400,000 florins, and became a port for the commerce of that city.