Jerusalem was held by the crusaders for nearly a century, while other strongholds in the Near East remained in Christian possession much longer. The crusades in the Holy Land ultimately failed to establish permanent Christian kingdoms. Islamic expansion into Europe remained a threat for centuries, culminating in the campaigns of Suleiman the Magnificent in the 16th century. Crusades in southern Spain, southern Italy, and Sicily eventually lead to the demise of Islamic power in Europe. Teutonic Knights expanded Christian domains in Eastern Europe, and the much less frequent crusades within Christendom, such as the Albigensian Crusade, achieved their goal of maintaining doctrinal unity.