Of all the events, inventions, and personalities that defined the European Middle Ages, none did more so than the Crusades. Beginning in the late eleventh century, the many kingdoms of western Europe awoke from their collective slumber to assert their power and place in the world by engaging in a series of religious wars in the Middle East, Spain, southern France, and the Baltic region. The strategic and tactical benefits of the Crusades were nominal at best for the Europeans: Jerusalem, the primary objective of the Crusaders, was taken during the First Crusade but later lost to the Muslims, never to be in Christian hands again.
Although the Crusaders may not have been able to keep their primary target, they were able to drive the Muslims from Spain and brought Christianity to the eastern Baltic region. The Crusades also helped to elevate the standing of the Roman Catholic Church and the western European kingdoms in the eyes of the Islamic and Orthodox Christian worlds – the Muslims and Orthodox Christians may not have liked the western Christians, but they learned to respect them and deal with them as equals. The Crusaders also brought back new knowledge of the world, in the form of math, science, and maps of the previously unknown when they returned to western Europe. Indeed, the Crusades benefited western Europe in many different ways but often overlooked are the economic benefits that the wars brought to Europe.
The Crusades allowed Europeans who would have previously been unable to own land to acquire lucrative estates in the Middle East. Europeans from all classes of society found ways to profit from the holy wars, and as a result, new banking methods were developed by the Order of the Knights Templar. But perhaps the Europeans who benefited the most economically from the Crusades were the Italian city-states, especially Venice, Pisa, and Genoa. As a result of the Crusades, the Italian merchant warriors were able to develop long-distance trade routes with the Near East, which led to the development of the Italian republics and helped spur the Renaissance.