He formed a navy of decisive preponderance in the western Mediterranean, and in return for services rendered to Francis in the Neapolitan campaign of 1528, he demanded the liberation of his native city.

When this was refused, Doria transferred his allegiance to the Spaniard, surprised Genoa and reinstated the republic, magnanimously refusing to secure its tyranny for himself or even to set the ducal cap upon his head.

Charles invested him with the principality of Melfi and made him a Grandee of Spain.

By this series of events Genoa was prepared to accept the yoke of Spanish influence and customs, which pressed so heavily in the succeeding century on Italy.
Charles had a body of 2000 Spaniards already quartered at Genoa, as well as strong garrisons in the Milanese, and a force of about 7000 troops collected by the Prince of Orange from the _debris_ of the army which had plundered Rome.

While he was on his road from Genoa to Bologna, this force was already moving upon Florence.