Meanwhile the western part of Belgium, the county of Flanders, had developed also in its own way. Assigned by the Treaty of Verdun to the kingdom of France, Flanders did not seek a separation from a country to which it was geographically attached and on whose territory were to be found the seats of its bishoprics and most of its monasteries. The political power of the house of Flanders dates from the time of Count Baldwin I, called Baldwin of the Iron Arm (879), an adventurous ruler, who violently took the daughter of the King of France, his lord, and made her his wife, notwithstanding the vehement protest of her royal father. That marriage brought to the count the rich possessions of his wife and furnished to his heirs an excellent pretext for meddling in the politics of France. The kings of France at the time of the first counts of Flanders were weaklings; moreover, the bishops of Noyon-Tournai, Arras, and Térouanne were not as loyal to their lord as those of Lotharingia were to the Emperor. The political conditions were thus quite different in Flanders, and at a time when the iron policy of Otto I and his heirs subdued the Lotharingian princes, the counts of Flanders succeeded in developing their independence and political influence without much opposition. Baldwin II (910) enlarged his domain by conquering the wealthy regions of Walloon-Flanders[7] and Artois and formed an alliance with England by marrying an Anglo-Saxon princess. Count Arnulf (918) took the title of marquess and tried—though vainly—to overpower the Duke of Normandy, who checked his advance in the south and with it the extension of Flemish conquest beyond the river Canche. Effectively blocked in their efforts to extend their power in the south, the Flemish counts next turned their attention to the north and the east. Successively the islands of Zeeland, the “Four Métiers,” and the county of Alost were subjugated, although already under the feudal authority of the German Empire. The result was that the Count of Flanders became at once a vassal of the King of France and of the German Emperor.
By the conquest of the county of Alost, Count Baldwin V was enabled to cross the Scheldt and to advance into Lotharingian territory. The marriage of his son with a princess of Hainaut resulted in uniting both Flanders and Hainaut under the same dynasty. Here again the barrier erected by the Treaty of Verdun was broken down, and for the first time political ties were established on both sides of the Scheldt, between the two parts of Belgium.
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.
After the Norman invasions of the ninth century, which left Belgium covered with ruins and with many churches and monasteries burned, or abandoned by their terrified occupants, the ecclesiastical discipline suffered severely. The old prescriptions of the Benedictine rule were no longer observed and most of the monasteries became dependents of powerful laymen.
In the tenth century a revival of the discipline followed, thanks to the efforts of St. Gerard of Brogne, founder of the little monastery of Brogne, near Namur (923). Gerard excited so much enthusiasm by the sanctity of his life and the rigor of his discipline that princes and bishops united in asking him to restore the practice of ascetic life both in Lotharingia and in Flanders. The number of the monasteries to the north of the linguistic barrier, especially in Flanders, soon increased, whereas before they were mainly to be found in Southern Belgium. Belgium became a country of monasteries in the eleventh century, and ever since that time the people have shown that deep religious spirit that is one of the distinctive traits of the national character. The monks exerted a very strong influence on the minds of the rough feudalists, who thought mainly of war and robbery: one of the most powerful dukes of Lotharingia, Godefrid the Bearded, desired to be buried in the dress of a monk. The robber-knights, pursuing an enemy or a convoy of merchants, thought only of plunder; once in sight of the walls of a monastery, however, they would cease their pursuit and turn back. Carrying through the country the relics of their saints, the monks would often succeed in stopping private wars and murder. An example of the religious spirit is the great “procession” of Tournai, that attracted every year thousands of pilgrims and visitors, Flemish and Walloon together, and that acted as a unifying factor for both races of Belgium.
The Reform of Cluny found the French and German influence in serious conflict. The reform in question, by which it was hoped to reintroduce a very severe discipline in the monastic world, originated in French Burgundy (1004) and soon spread through the northern countries, especially in Flanders and Lotharingia. The monks of Cluny resolutely resented any interference of the temporal power in religious affairs. As a result they found themselves practically opposed to the system of the imperial and feudal church of Germany, dominated by the Emperor. The destruction of that system thus meant indirectly the destruction of German influence in Lotharingia. When the Struggle for the Investitures broke out, the Lotharingian bishops hesitated at first, but after a while nearly all of them took sides with the papal cause against the Emperor. Both in matters of politics and religion Lotharingia tended more and more to break away from Germany.