A large Venetian fleet sailed up the Po, while two armies attacked the Ferrarese territory—Sanseverino from the Lombard side and Malatesta from that of Romagna. Rovigo and the whole Polesina fell into the hands of the Venetians, whose commander-in-chief encamped, on May 28, before Ficcarolo—a castle situated on the Po to the north-west of Ferrara—intending to take it, and then to cross the river and attack the capital, Malatesta co-operating with him from the south side. But meanwhile the Duke of Urbino, with the Milanese troops, raised his camp at Stellata, on the right bank, to assist the besieged and cover Ferrara; and Malatesta was called away from the Po district to meet a threatened danger in an opposite quarter. Alfonso of Calabria had appeared at the Tronto, demanding a free pass to bring aid to his brother-in-law. The Pope had not yet declared himself; the envoys of Naples, Milan, Florence, and Ferrara were still in Rome. On the refusal of the pass they left the city, and the duke entered the States of the Church as an enemy. He met no serious resistance. Rome resounded with the clang of arms; as an annalist says, ‘The city which had hitherto been wont to produce only bulls and briefs now produced nothing but arms.’[236] Girolamo Riario had the post of captain-general for the Church, but his incapacity soon became apparent. The Neapolitans were at Grottaferrata; their horsemen made excursions to the very gates of the city; vineyards and fields were laid waste. This state of things continued for weeks. At last the Pope saw himself compelled to appeal for help to Venice, and she ordered Roberto Malatesta to go to the assistance of her hard-pressed ally. Meanwhile, the Florentines had made a diversion; Niccolò Vitelli, supported by Costanzo Sforza, had taken Città di Castello on June 19, and the whole country around had fallen into his hands.