On the death of Clement VI. he was succeeded by Innocent VI. He was an ignorant man; and, from Petrarch's perpetual study of Virgil (who was reputed to be an adept in the art magic), he fancied that the poet was a magician also. [Sidenote: 1352. Ætat. 48.] Petrarch was now most anxious to return to Italy, yet still lingered at Vaucluse. He made an excursion to visit the Carthusian convent, where his brother Gerard had taken the vows. Gerard had acted an admirable and heroic part during the visitation of the plague, and survived the dangers to which he fearlessly exposed himself. Petrarch was received in his monastery with respect and affection; and, in compliance with the request of the monks, wrote his treatise "On Solitary Life." Winter advanced, and he was most anxious to cross the Alps. He visited his old friend, the bishop of Cavaillon, at Cabrières, and was entreated by him to remain "one day more." Petrarch consented with reluctance; and on that very night such storms came on, as impeded his journey for several weeks. [Sidenote: 1353. Ætat. 49.] At length he crossed the Alps, and arrived at Milan, on his way southward, not having determined in his own mind in what town he should fix his residence, wavering between Parma, Padua, Verona, and Venice. While in this state of indecision, the hospitable reception and earnest invitation of Giovanni Visconti, lord and bishop of Milan, induced him to remain in that city. Louis of Baviere, emperor of Germany, had been deposed by pope John XXII., and each succeeding pontiff confirmed the interdict. Clement VI. raised Charles, the son of John of Luxembourg, king of Bohemia, to the imperial throne, imposing on him, at the same time, rigorous and disgraceful conditions with regard to his rights over Italy, forcing him into an engagement never to pass a single night at Rome, but enter it merely for the ceremony of his coronation. Charles and his father had visited Avignon in the year 1346, to arrange the stipulations.[55] Some time after, Petrarch wrote a long and eloquent letter to the emperor, imploring him to enter Italy, and to deliver it from the disasters that oppressed it. It is singular that two such lovers of their country, as Dante and Petrarch, should both have invited German emperors to take possession of it: but the emperor was then the representative of the sovereigns of the Western empire, and they believed that, crowned and reigning at Rome, that city would again become the capital of the world, and Germany sink into a mere province. For though Petrarch earnestly implores the emperor to enter Italy, various imprecations against the Germans are scattered through his poems. [Sidenote: 1354. Ætat. 50.]