A bridge, as already stated, was built at Cambridge in the ninth century, but in 870, and again in 1010, the Danes sacked the town, and it would seem that the bridge was destroyed, for early in the twelfth century we find a reference to the ferry being definitely fixed at Cambridge, and that before that time it had been "a vagrant," passengers crossing anywhere that seemed most convenient. This fixing of the ferry, and various favours bestowed by Henry I., resulted in an immediate growth of prosperity, and the change was recognized by certain Jews who took up their quarters in the town and were, it is interesting to hear, of such "civil carriage" that they incurred little of the spite and hatred so universally prevalent against them in the Middle Ages. The trade guilds of Cambridge were founded before the Conquest, and, becoming in course of time possessed of wealth and influence, some of them were enabled to found a college.
As England settled down under the Norman Kings, the great Abbey of Ely waxed stronger and wealthier, and in the wide Fen Country there also grew up the abbeys of Peterborough, Crowland, Thorney, and Ramsey--all under the Benedictine rules. To the proximity of these great monasteries was due the beginning of the scholastic element in Cambridge, and perhaps the immense popularity of Stourbridge Fair, which Defoe thought the greatest in Europe, may have helped to locate the University there. Exactly when or how the first little centre of learning was established in the town is still a matter of uncertainty, but there seems to have been some strong influence emanating from the Continent in the twelfth century which encouraged the idea of establishing monastic schools. Cambridge in quite early times began to be sprinkled with small colonies of canons and friars, and in these religious hostels the young monks from the surrounding abbeys were educated. Mr. A.H. Thompson, in his _Cambridge and its Colleges_, suggests that the unhealthy dampness of the fens would have made it very desirable that the less robust of the youths who were training for the cloistered life in the abbeys of East Anglia should be transferred to the drier and healthier town, where the learning of France was available among the many different religious Orders represented there.