At the period at which we have arrived, by virtue of one of the periodical movements of the political see-saw, of which both so often felt the effects, François's situation had recently improved, and Charles's grown worse in equal degree. In fact, things had changed materially since the Treaty of Cambrai, which was negotiated by two women, Margaret of Austria, aunt of Charles V., and the Duchesse d'Angoulême, mother of François I. This treaty, which was the complement of the treaty of Madrid, provided that the King of Spain should cede Burgundy to the King of France, and that the King of France should renounce his claim to the homage of Flanders and Artois. Furthermore, the two young princes, who served as hostages for their father, were to be sent back to him in exchange for the sum of two millions of golden crowns. Lastly, good Queen Eleanora, Charles V.'s sister, who was promised at first to the Constable (Bourbon) as a reward for his treachery, and was afterwards married to François as a pledge of peace, was to return to the court of France with the two children, to whom she had been as affectionate and devoted as any mother. These stipulations were carried out with equal good faith on both sides. But it will readily be believed that François's renunciation of his claim to the Duchy of Milan, exacted from him during his captivity, was only momentary. He was no sooner a free man once more, no sooner restored to power and health, than he turned his eyes again toward Italy. It was with the object of procuring countenance of his claims at the Court of Rome that he had married his son Henri, become Dauphin by the death of his elder brother François, to Catherine de Medicis, niece of Pope Clement VII. Unfortunately, just at the moment when all the preparations for the king's meditated invasion were completed, Clement VII. died, and was succeeded by Alexander Farnese, who ascended the throne of St. Peter under the name of Paul III. Now Paul III. was determined not to allow himself to be inveigled into supporting the party of the Emperor, or of the King of France, but to adhere strictly to the policy of holding an equal balance between them. With his mind at ease in that direction, the Emperor laid aside all anxiety on the subject of the preparations of France, and busied himself fitting out an expedition against Tunis, which had been seized by the corsair Cher-Eddin, so famous under the name of Barbarossa, who, having driven out Muley Hassan, had taken possession of the country, and was laying Sicily waste. The expedition was entirely successful, and Charles V., after destroying three or four ships, sailed into the Bay of Naples in triumph.