Meanwhile Beatrix and Christina returned to Milan, and spent the summer together in the Castello. A close friendship sprang up between the two Duchesses. Beatrix took a motherly interest in her young companion, and the children's presence helped to cheer these anxious months. At first the Emperor's arms were entirely successful. The French retired before him to Avignon, laying the country waste, and he met with no opposition until he reached Aix, which resisted all his attacks. During the long siege which followed, his soldiers suffered severely from disease and famine, and many youths of the noblest Milanese families were among the victims.[137] Early in September, while Christina's own secretary, Belcorpo, was robbed and murdered on his way to the camp, Antonio de Leyva, the redoubtable Commander-in-Chief, died, and was buried in S. Eustorgio at Milan. The Papal Legate, Cardinal Caracciolo, a Neapolitan by birth, was appointed to succeed him as Viceroy of Milan. He had only just assumed the reins of office, and paid his first visit to the young Duchess, when he received a summons from the Emperor to join him at Genoa. Finding it impossible to reduce Aix, Charles had determined to abandon the campaign, and on the 16th of November a three months' truce was signed between the two monarchs. The Emperor was anxious to return to Spain, where his presence was sorely needed. But before his departure he sent for the Cardinal, desiring him to leave some trusty lieutenant to govern the State in his absence, and take charge of his niece the Duchess. Accordingly, Caracciolo went to Genoa on the 4th of October, accompanied by Beatrix of Savoy, who, after a long interview with the Emperor, joined her husband at Nice, the only city which still belonged to him. Soon after this her health gave way under the prolonged strain, and this once brilliant and beautiful woman died in January, 1538, as she said herself, of a broken heart. Christina, now left alone at Milan, wrote a long letter to the Cardinal, whom she addressed in the language of a caressing child, saying that he was dear to her as a father, and seeking his help for two objects which lay very near her heart. "The true affection," she writes, "which Your Excellency has shown me, and the kind remembrance of me which you always keep, makes me anxious for your health and welfare. So I beg you to tell me how you have prospered on your journey, and if you are well in health."