The Economic Effect of the Crusades is enhanced existing trade

The Economic Effect of the Crusades is enhanced existing trade. The Political Effect of the Crusades is kings took control of the lands left unoccupied, giving the kings more power. The Social Effect of the Crusades is some people began to respect other cultures, but others viewed non-Christians as enemies.
One of the most important effects of the crusades was on commerce. They created a constant demand for the transportation of men and supplies, encouraged ship-building, and extended the market for eastern wares in Europe. The products of Damascus, Mosul, Alexandria, Cairo, and other great cities were carried across the Mediterranean to the Italian seaports, whence they found their way into all European lands. The elegance of the Orient, with its silks, tapestries, precious stones, perfumes, spices, pearls, and ivory, was so enchanting that an enthusiastic crusader called it “the vestibule of Paradise.” The most important effect of the Crusades was economic. The Italian cities prospered from the transport of Crusaders and replaced Byzantines and Muslims as merchant-traders in the Mediterranean. Trade passed through Italian hands to Western Europe at a handsome profit. This commercial power became the economic base of the Italian Renaissance. It also provoked such Atlantic powers as Spain and Portugal to seek trade routes to India and China. Their efforts, through such explorers as Vasco da Gama and Christopher Columbus, helped to open most of the world to European trade dominance and colonization and to shift the center of commercial activity from the Mediterranean to the Atlantic.
The Crusades had far-reaching political, economic, and social impacts, some of which have lasted into contemporary times. Because of internal conflicts among Christian kingdoms and political powers, some of the crusade expeditions were diverted from their original aim, such as the Fourth Crusade, which resulted in the sack of Christian Constantinople and the partition of the Byzantine Empire between Venice and the Crusaders. The Sixth Crusade was the first crusade to set sail without the official blessing of the Pope, establishing the precedent that rulers other than the Pope could initiate a crusade. The Seventh, Eighth and Ninth Crusades resulted in Mamluk and Hafsid victories, as the Ninth Crusade marked the end of the Crusades in the Middle East.