Here was the secret! Unfortunately for the Reformation, policy was supposed to make it an imperative duty to conciliate the favor of the Pope, no less after the release of Francis than while he was yet a prisoner. There were the young princes sent by the regent as hostages for the fulfilment of the treaty with Charles of Spain, for whose liberation measures were to be devised. And there was the oath--to the shame of Francis, it must be added--from the binding force of which the king hoped to be relieved by authority of the Roman bishop; for scarcely had Francis set foot on his own dominions, when he unblushingly retracted all his treaty stipulations. He announced to the emperor that the cession of Burgundy, the Viscounty of Auxonne, and other territories, which had been made by his imperial captor the indispensable condition of his release, was entirely out of the question; and that his promises, extorted while he was in duress, were of no validity! Nevertheless, he offered, in lieu thereof, the payment of a larger ransom than had ever been proffered by a king of France. Indignant at a perfidy somewhat flagrant, even for an age tolerably well accustomed to breaches of faith, the emperor refused the substitute. The arms recently laid aside were resumed. Clement the Seventh and Venice became the allies of Francis, who for the present figured as the champion of the papacy; while his rival, by suffering the traitor Constable de Bourbon with an army of German soldiers to besiege the pontiff in his capital, became responsible in the eyes of the world for all the atrocities of the famous sack of the city of Rome. When, at length, after three years of hard fighting, peace was concluded by the treaty of Cambray (July, 1529), the terms agreed upon at Madrid were virtually carried into effect; but the emperor consented to receive the sum of two millions of Crowns--_êcus-au-soleil_--in place of Burgundy, and on payment to restore to the French the dauphin and the Duke of Orleans, the future Henry the Second, so long detained as hostages in Spain. [Sidenote: The king's necessities.] [Sidenote: A despotic course suggested.]