Coincident with the first signs of a tendency to union between Eastern and Western Belgium, Flanders began to come into closer contact with foreign countries and powers. As the daughter of Baldwin V was married to William the Conqueror, Duke of Normandy, many Flemish troops took part in the conquest of England by the Normans (1066), and these remained in the British Isles for purposes of colonization. Diplomatic and commercial relations between Flanders and England were the happy result. Under Count Robert (1070), Flanders came into contact with Denmark and with the court of Rome; a pilgrimage to Jerusalem undertaken by Robert brought him into touch with the Emperor of Constantinople, and the Count of Flanders happened to be the first prince of Europe to consider a crusade against the Turks. In the twelfth century, however, the political expansion of Flanders came to a standstill. To the weaklings of the former period in France there had now succeeded kings of stronger character, whose policy led them to subdue their restless vassals and to centralize their own power. They sought, therefore, to check the expansion of Flanders and to dominate the powerful county, attaching it more closely to the French domain. The road to the south was thus no longer open for eventual conquest; the road to the east also was barred by the Lotharingian princes. The influence of the German Empire had practically disappeared in Lotharingia. Brabant and Hainaut now became the centers of a strong political life. It is a curious phenomenon of history that, when Flanders was threatened by the growing strength of France, Lotharingia became practically independent of the influence of the German Empire. There was, therefore, as has been seen, no political unity in Belgium during the feudal period: east and west each developed in its own way and political conditions in each section were very strongly influenced by their powerful neighbors. There did exist, however, a common tendency toward autonomy and freedom, Flanders trying to escape from the influence of France and, to some extent, that of England;[8] Lotharingia struggling against the hegemony of Germany. That tendency, it must be admitted, is not a purely characteristic Belgian movement. At this period the feudalists were everywhere to be found fighting against the supremacy of the King and trying to win complete political independence for themselves. The one essentially Belgian factor in the diverging existence of the east and the west, and which exerted a strong influence in favor of unification, was the common social, economic, and religious life. A study of religious conditions in Belgium during the tenth and eleventh centuries reveals, even more clearly than a study of political events, the part played by both Germany and France in imposing their respective practices, and the ability of Belgium to incorporate and to modify the best elements of Teutonic and Latin civilization.