Anticipating this threatened danger, the Duke of Alva marched an army of fourteen thousand men into the Comarca, which he overran in September, occupying Tivoli on the one hand, and Ostia on the other, whilst Marc-Antonio Colonna scoured the Campagna, to the gates of Rome. Guidobaldo, who appears to have been about this time superseded, and his truncheon of command transferred to the Pontiff's favourite nephew, contented himself with sending a contingent of two thousand troops, under Aurelio Fregoso, for his Holiness's support. The efforts made on all sides to conclude a harassing and useless war, were rendered unavailing by the Pope's obstinacy and ambition; the only terms he would agree to including an investiture of his nephew as sovereign of Siena, in compensation for the Colonna estates. During the winter months, a horde of northern barbarians were once more mustered to invade unhappy Italy. Fourteen thousand Gascons, Grisons, and Germans, under command of the Duc de Guise, marched early in the spring upon Romagna, which, though a friendly country, they cruelly ravaged. Faenza having escaped their brutality by denying them entrance, its citizens testified their gratitude for the exemption, by instituting an annual triduan thanksgiving, and dotation of two of their daughters. The Duke of Urbino did his best to secure his people during the transit of this army, which crossed the Tronto in April. It would be tedious to follow the fortunes of a campaign in which he took no part, and which, whoever gained, was the scourge of Italy. On the 26th of August, the Duc de Guise placed his scaling ladders against the San Sebastiano gate, and Rome had nearly been carried by a coup-de-main. At length the representations of Venice and Florence, which had remained neutral, prevailed with his Holiness, and, on the 14th of September, peace was restored, leaving matters much on their former footing. Riposati assures us that during this war the French monarch would gladly have secured the services of Guidobaldo, now free from his engagements to the Pontiff, but that Duke Cosimo of Florence interested himself to procure for him an engagement from Spain. This was at length arranged, in the spring of 1558, previously to which Charles V. appears to have bestowed on him the Golden Fleece, the highest compliment at his disposal.[61] [Footnote 61: Some authorities represent him as receiving this Order eleven years later from Charles V., but that Emperor died in this very year. He is said to have had knighthood from the Pope in 1561.]