The six years of repose, however, which this truce guaranteed, accustomed the emperor to submit to limitations of his authority. Thirty years had passed since the contest had begun between him and the Italian nation; age had now tempered his activity and calmed his pride. New incidents had arisen in Germany to fix his attention. His son, Henry VI, demanded to be associated in the sovereignty of his two kingdoms of Germany and Italy. A definitive peace only could restore to Frederick his rights and revenues in Lombardy, which his subjects there did not dispute, but which the truce held suspended. The adverse claims were honestly weighed at the Diet of Constance; reciprocal concessions were made both by the monarch and his subjects, and the Peace of Constance, the basis of new public rights for Italy, was at length signed on the 25th of June, 1183. By this peace the emperor renounced all regal privileges which he had hitherto claimed in the interior of towns. He acknowledged the right of the confederate cities to levy armies, to enclose themselves within fortifications, and to exercise by their commissioners within their own walls both civil and criminal jurisdiction. The consuls of towns acquired by the simple nomination of the people all the prerogatives of imperial vicars. The cities of Lombardy were further authorised to strengthen their confederation for the defence of their just rights, recognised by the Peace of Constance. But, on the other side, they engaged to maintain the just rights of the emperor, which were defined at the same time; and in order to avoid all disputes, it was agreed that these rights might always be bought off by the annual sum of two thousand marks of silver. Thus terminated, in the establishment of a legal liberty, the first and most noble struggle which the nations of modern Europe have ever maintained against despotism. [Illustration: AN ITALIAN OFFICER, TWELFTH CENTURY] The generous resistance of the Lombards, during a war of thirty years, had conquered from the emperors political liberty for all the towns of the kingdom of Italy. The right of obeying only their own laws, of being governed by their own magistrates, of contracting alliances, of making peace or war, and, in fine, of administering their own finances, with the exception only of a certain revenue payable into the imperial treasury, was more particularly secured by the Peace of Constance to the confederate cities of the league of Lombardy.