The physicians at length despaired of his life, and informed Charles that they saw no hope of his recovery unless he was granted the interview he so deeply desired. This news put the emperor into a quandary. If Francis should die, all the advantage gained from the battle of Pavia would be lost. And there were clouds in the sky elsewhere. Henry VIII. had concluded a treaty of alliance with Queen Louise, regent of France, and engaged to use all his efforts for the release of the king. In Italy a dangerous conspiracy had been detected. There was danger of a general European confederacy against him unless he should come to some speedy agreement with the captive king. Charles, moved by these various considerations, at length visited Francis, and, with a show of respect and affection, gave him such promises of speedy release and princely treatment as greatly cheered the sad heart of the captive. The interview was short; Francis was too ill to bear a long one; but its effect was excellent, and the sick man at once began to recover, soon regaining his former health. Hope had proved a medicine far superior to all the drugs of the doctors. But the obdurate captor had said more than he meant. Francis was kept as closely confined as ever. And insult was added to indignity by the emperor’s reception of the Constable Bourbon, a traitorous subject of France, whom Charles received with the highest honors which a monarch could show his noblest visitor, and whom he made his general-in-chief in Italy. This act had a most serious result, which may here be briefly described. In 1527 Bourbon made an assault on Rome, with an army largely composed of Lutherans from Germany, and took it by assault, he being killed on the walls. There followed a sack of the great city which had not been surpassed in brutality by the Vandals themselves, and for months Rome lay in the hands of a barbarous soldiery, who plundered and destroyed without stint or mercy. What Charles mainly insisted upon and Francis most indignantly refused was the cession of Burgundy to the German empire. He was willing to yield on all other points, but bitterly refused to dismember his kingdom. He would yield all claim to territory in Italy and the Netherlands, would pay a large sum in ransom, and would make other concessions, but Burgundy was part of France, and Burgundy he would not give up.