As a direct result of this centralisation tendency and of the increase in royal authority that it involved, the rulers of Europe initiated a campaign against all constitutional restrictions on the exercise of their authority. The feudal system with all its faults was in some senses wonderfully democratic. The sovereign was dependent upon the decisions of the various representative assemblies; and though the lower classes had little voice except in purely local affairs, yet the rights and privileges of all classes were hedged round so securely by written charters or immemorial usage that any infringement of them might be attended with serious results. In England the Parliament, in Spain the Cortes, in France the States General, and in Germany the Diet, should have proved a strong barrier against absolute rule. But the authority of such assemblies was soon weakened or destroyed. Under the Tudors the English Parliament became a mere machine for registering the wishes of the sovereign; the Cortes and States General were rarely consulted in Spain and France; and, though the Diet retained its position in the Empire, it was used rather to increase the influence of the princes than to afford any guarantee of liberty to the subject. In bringing about such a complete revolution the rulers were assisted largely by the introduction of the Roman Code of Justinian.[1] According to the principles of the Roman Code the power of the sovereign was unlimited, and against his wishes no traditional customs or privileges could prevail. Such a system was detested especially by the Germans, who clung with great pertinacity to their own national laws and customs; but the princes, supported by the universities, carried through the reform on which they had set their heart. They succeeded in strengthening their own power and in trampling down the rights guaranteed to their subjects by the old Germanic Code, while at the same time they were untiring in their resistance to imperial reforms, and were unwilling to do anything to increase the power of the Emperor.