As a matter of fact, in 1170, strong efforts had been made to bring about such a consummation. But Frederick was bound by the Wuerzburg decrees, and his envoy could not offer the submission that Alexander required.
John of Salisbury tells us that the Emperor made a proposition to the effect that he himself, for his own person, should not be compelled to recognize any pope "save Peter and the others who are in heaven," but that his son Henry, the young King of the Romans, should recognize Alexander, and, in return, receive from him the imperial coronation. The bishops ordained by Frederick's popes were to remain in office. Alexander answered these proposals with a certain scorn, and the imperial ambassador, Eberhard of Bamberg, returned from Veroli, where the conference had taken place, with nothing to show for his pains.
Alexander's next move was to send an account of the interview to the heads of the Lombard League, and at the same time to consecrate, as it were, that organization. He declared that it had been formed for the purpose of defending the peace of the cities which composed it, and of the Church, against the "so-called Emperor, Frederick," whose yoke it had seen fit to cast off. The rectors of the confederation were taken under the wing of the papacy, and those who should disobey them threatened with the ban. The Pope recommended a strict embargo on articles of commerce from Tuscany should the cities of that province refuse to join the league.
At this same time Alexander showed his friendliness toward the Eastern Empire by performing in person the marriage ceremony over the niece of the Emperor Manuel and one of the Roman Frangipani.
Frederick's first act on entering Italy in 1174 was to wreak vengeance on Susa, where he had once been captive; no half measures were used, and the town was soon a heap of ashes. Asti, also, the first league town which lay in the path of the imperial army, was straightway made to capitulate. But, although the fall of these two cities induced many to abandon the cause of the league, the new fortress of Alessandria, situated as it was in the midst of a swampy plain and surrounded with massive earth walls, proved an effectual stumbling-block in the way of the avenger. Heavy rains and floods came to the aid of the besieged city and the imperial tents and huts were almost submersed, while hunger and other discomforts caused many of the allies of the Germans to desert. The siege was continued for six months, but Frederick at last abandoned it on learning that an army of the league was about to descend on his weakened forces. He burned his besieging implements, his catapults, battering rams, and movable towers, and retreated to Pavian territory.
The forces of the allied cities were sufficient to alarm Frederick, but they did not follow up their advantage. One is surprised to find negotiations for a peace begun at a time when a decisive battle seemed imminent. What preliminary steps were taken, or why the Lombards should have been the first to take them, is not clear; although some slight successes gained by Christian of Mayence at this juncture in the neighborhood of Bologna may have been not without effect.
A commission of six men was appointed to draw up the articles of treaty, three being chosen from the cities, three appointed by the Emperor. The consuls of Cremona were to decide on disputed points—points, namely, as to which it was impossible to arrive at a mutual agreement. A truce to all hostilities was meanwhile declared, and at Montebello both sides bound themselves to concur in whatever arrangement should be made by the commission and the consuls. The Lombards meanwhile went through the form of a submission, knelt at the Emperor's feet, and lowered their standards before him. Frederick thereupon received them into favor and dismissed the greater part of his army, the league doing likewise.
Naturally enough the disputed points were the most important ones, and had to be referred to the consuls of Cremona. But the rage and disappointment of the Lombards went beyond bounds when the different decisions, which, indeed, were remarkably fair, at last were made known. The Emperor was to exercise no prerogatives in Northern Italy that had not been exercised in the time of Henry V; he was also to sanction the continuance of the league. But no arrangement was made for a peace between the heads of Christendom, although the league had made this its first demand. Then, too, Alessandria, which Frederick considered to have been founded in scorn of himself, was to cease to exist, and its inhabitants were to return to their former homes.
The report of the consuls roused a storm of indignation; in many cases the document embodying it was torn in shreds by the mob. The Lombards altogether refused to be bound by the terms of the treaty, and reopened hostilities. Frederick hastily gathered what forces he could and sent a pressing call to Germany for aid.
It was now that the greatest vassal of the Crown, Henry the Lion, rewarded twenty years of trustfulness and favor by deserting Frederick in his hour of need. The only cause that is known, a strangely insufficient one, was a dispute concerning the town of Goslar, which the Emperor had withdrawn from Henry's jurisdiction. The details of the meeting, which took place according to one chronicle at Partenkirchen, to another at Chiavenna, are but vaguely known to us, but Frederick is said to have prostrated himself at the feet of his mighty subject and to have begged in vain for his support.