As far as the city of Rome itself is concerned, small account was taken of its internal agitations, so many were the Popes who had returned after being expelled by popular tumult, and so greatly did the presence of the Curia minister to the interests of the Roman people. But Rome not only displayed at times a specific anti-papal radicalism,[224] but in the most serious plots which were then contrived, gave proof of the working of unseen hands from without. It was so in the case of the conspiracy of Stefano Porcaro against Nicholas V. (1453), the very Pope who had done most for the prosperity of the city, but who, by enriching the cardinals, and transforming Rome into a papal fortress, had aroused the discontent of the people.[225] Porcaro aimed at the complete overthrow of the papal authority, and had distinguished accomplices, who, though their names are not handed down to us,[226] are certainly to be looked for among the Italian governments of the time. Under the pontificate of the same man, Lorenzo Valla concluded his famous declamation against the gift of Constantine, with the wish for the speedy secularisation of the States of the Church.[227] The Catilinarian gang, with which Pius II. had to contend[228] (1460), avowed with equal frankness their resolution to overthrow the government of the priests, and its leader, Tiburzio, threw the blame on the soothsayers, who had fixed the accomplishment of his wishes for this very year. Several of the chief men of Rome, the Prince of Tarentum, and the Condottiere Jacopo Piccinino, were accomplices and supporters of Tiburzio. Indeed, when we think of the booty which was accumulated in the palaces of wealthy prelates--the conspirators had the Cardinal of Aquileia especially in view--we are surprised that, in an almost unguarded city, such attempts were not more frequent and more successful. It was not without reason that Pius II. preferred to reside anywhere rather than in Rome, and even Paul II.[229] was exposed to no small anxiety through a plot formed by some discharged abbreviators, who, under the command of Platina, besieged the Vatican for twenty days. The Papacy must sooner or later have fallen a victim to such enterprises, if it had not stamped out the aristocratic factions under whose protection these bands of robbers grew to a head.