The First Crusade was launched in 1095 by Pope Urban II with the dual goals of liberating the sacred city of Jerusalem and the Holy Land from Muslims and freeing the Eastern Christians from Muslim rule. What started as an appeal by Byzantine Emperor Alexios I Komnenos for western mercenaries to fight the Turks in Anatolia quickly turned into a wholesale Western migration and conquest of territory outside of Europe. Both knights and peasants from many nations of Western Europe, with little central leadership, travelled over land and by sea towards Jerusalem and captured the city in July 1099, establishing the Kingdom of Jerusalem and other Crusader states. Although these gains lasted for less than two hundred years, the First Crusade was a major turning point in the expansion of Western power, as well as the first major step towards reopening international trade in the West since the fall of the Western Roman Empire. It was also the most successful crusade, being the only one to succeed in capturing Jerusalem.