by Nicholas and emptied into a simple basin that Alberti designed, the predecessor of the Trevi Fountain. He continued restoration of the major Roman basilicas, but also of many other Roman churches including Sant' Apostoli, Sant' Eusebio, San Lorenzo fuori le Mura, Santa Maria in Trastevere, Santa Prassede, San Salvatore, Santo Stefano Rotondo, San Teodoro, and especially San Celso. He rebuilt the Ponte Sant' Angelo which had collapsed in 1450, and supported the redevelopment of the surrounding area as a prestigious business and residential district. Arts patron Nicholas V's major focus was on establishing the Vatican as the official residence of the Papacy, replacing the Lateran Palace. He added a substantial new wing including a private chapel to the Vatican, andaccording to Giannozzo Manetti, biographer of Nicholasplanned substantial changes to the Borgo district. He also laid up 2,522 cartloads of marble from the dilapidated Colosseum for use in the later constructions. The Pope's contemporaries criticised his lavish expenditure on building: Manetti drew parallels with the wealth and expenditure of Solomon, suggesting that Papal wealth was acceptable so long as it was expended to the glory of God and the good of the Church. The decoration of the Niccoline Chapel by Fra Angelico demonstrated this message through its depictions of St Lawrence (martyred for refusing to hand to the Roman state the wealth of the Church) and St Stephen. Under the generous patronage of Nicholas, humanism made rapid strides as well. The new humanist learning had been hitherto looked on with suspicion in Rome, a possible source of schism and heresy from an unhealthy interest in paganism. For Nicholas, humanism became a tool for the cultural aggrandizement of the Christian capital, and he sent emissaries to the East to attract Greek scholars after the fall of Constantinople. The pope also employed Lorenzo Valla to translate Greek histories, pagan as well as Christian, into Latin. This industry, coming just before the dawn of printing, contributed enormously to the sudden expansion of the intellectual horizon. Nicholas, with assistance from Enoch of Ascoli and Giovanni Tortelli, founded a library of five thousand volumes, including manuscripts rescued from the Turks after the fall of Constantinople. The Pope himself was a man of vast erudition, and his friend Aeneas Silvius Piccolomini, later Pope Pius II, said of him that "what he does not know is outside the range of human knowledge". A lifelong bibliophile, he treasured