The Crusades were a series of wars between Christians and Muslims during the Middle Ages. Western European Christians sought to gain control of Palestine, the land where Jesus lived, died, and according to Christians, was resurrected, from the Muslims. While Christian Crusaders never achieved more than temporary control of Jerusalem, the Crusades had many lasting effects on Western European societies. These effects profoundly changed the lives of Western Europeans. One of the many effects of the Crusades was that the pope and the kings of Western Europe became more powerful. In addition, Europeans began to trade with the Middle East. Trade increased as Western Europeans began to buy products like sugar, lemons, and spices. Naturally, increased trade led to increased cultural diffusion. Crusaders and traders learned about Arab art, architecture, medicine, and mathematics. Since the Arabs were very advanced in science and mathematics, Western European knowledge increased. Finally, after traveling to the Middle East, may Western Europeans began to see their small villages as uninteresting and even boring. Many Western Europeans began to seek adventure. Exploration increased.