This arrangement was guaranteed by two bankers in Rome who were to be responsible for 15,000 ducats, the sum total of the expenses which the governor pretended he had incurred in the place on the duke's account.
The pope on his part engaged to send Caesar to Ostia under the sole guard of the Cardinal of Santa Croce and two officers, who were to give him his full liberty on the very day when his engagements were fulfilled: should this not happen, Caesar was to be taken to Rome and imprisoned in the Castle of Sant' Angelo.

In fulfilment of this treaty, Caesar went down the Tiber as far as Ostia, accompanied by the pope's treasurer and many of his servants.

The Cardinal of Santa Croce followed, and the next day joined him there.
But as Caesar feared that Julius II might keep him a prisoner, in spite of his pledged word, after he had yielded up the fortresses, he asked, through the mediation of Cardinals Borgia and Remolina, who, not feeling safe at Rome, had retired to Naples, for a safe-conduct to Gonzalva of Cordova, and for two ships to take him there; with the return of the courier the safe-conduct arrived, announcing that the ships would shortly follow.
In the midst of all this, the Cardinal of Santa Croce, learning that by the duke's orders the governors of Cesena and Bertinoro had surrendered their fortresses to the captains of His Holiness, relaxed his rigour, and knowing that his prisoner would some day or other be free, began to let him go out without a guard.

Then Caesar, feeling some fear lest when he started with Gonzalvo's ships the same thing might happen as on the occasion of his embarking on the pope's vessel--that is, that he might be arrested a second time--concealed himself in a house outside the town; and when night came on, mounting a wretched horse that belonged to a peasant, rode as far as Nettuno, and there hired a little boat, in which he embarked for Monte Dragone, and thence gained Naples.

Gonzalvo received him with such joy that Caesar was deceived as to his intention, and this time believed that he was really saved.