This task was undertaken by the terrible Sixtus IV. He was the first Pope who had Rome and the neighbourhood thoroughly under his control, especially after his successful attack on the House of Colonna, and consequently, both in his Italian policy and in the internal affairs of the Church, he could venture to act with a defiant audacity, and to set at nought the complaints and threats to summon a council which arose from all parts of Europe. He supplied himself with the necessary funds by simony, which suddenly grew to unheard-of proportions, and which extended from the appointment of cardinals down to the granting of the smallest favours.[230] Sixtus himself had not obtained the papal dignity without recourse to the same means. A corruption so universal might sooner or later bring disastrous consequences on the Holy See, but they lay in the uncertain future. It was otherwise with nepotism, which threatened at one time to destroy the Papacy altogether. Of all the ‘nipoti,’ Cardinal Pietro Riario enjoyed at first the chief and almost exclusive favour of Sixtus. He soon drew upon him the eyes of all Italy,[231] partly by the fabulous luxury of his life, partly through the reports which were current of his irreligion and his political plans. He bargained with Duke Galeazzo Maria of Milan (1473), that the latter should become King of Lombardy, and then aid him with money and troops to return to Rome and ascend the papal throne; Sixtus, it appears, would have voluntarily yielded it to him.[232] This plan, which, by making the Papacy hereditary, would have ended in the secularization of the papal state, failed through the sudden death of Pietro. The second ‘nipote,’ Girolamo Riario, remained a layman, and did not seek the Pontificate. From this time the ‘nipoti,’ by their endeavours to found principalities for themselves, became a new source of confusion to Italy. It had already happened that the Popes tried to make good their feudal claims on Naples in favour of their relatives;[233] but since the failure of Calixtus III. such a scheme was no longer practicable, and Girolamo Riario, after the attempt to conquer Florence (and who knows how many other places) had failed, was forced to content himself with founding a state within the limits of the papal dominions themselves. This was, in so far, justifiable, as Romagna, with its princes and civic despots, threatened to shake off the papal supremacy altogether, and ran the risk of shortly falling a prey to Sforza or the Venetians, when Rome interfered to prevent it. But who, at times and in circumstances like these, could guarantee the continued obedience of ‘nipoti’ and their descendants, now turned into sovereign rulers, to Popes with whom they had no further concern? Even in his lifetime the Pope was not always sure of his own son or nephew, and the temptation was strong to expel the ‘nipote’ of a predecessor and replace him by one of his own. The reaction of the whole system on the Papacy