The edifice thus commenced was carried on by Baccio Pontelli, a Florentine artist, who, though designing himself a carpenter, was much employed by Sixtus IV. to erect important fabrics in Rome. It is impossible now to decide whether he was at first assistant to Lauranna, or what portion of the Corte we owe to him, the entire credit of which seems claimed in a presumptuous epitaph, apparently of his own composition, which is given by Gaye.[121] He was employed upon it in 1481, when applied to by Lorenzo de' Medici to furnish a design or plan of the already famous work, a request handsomely responded to by Federigo, in that almost oriental exaggeration of compliment still usual in Lower Italy, with the assurance that such a wish was a command, and that he only regretted being unable to send him the building itself, of which he might fully dispose. Baccio's letter mentions it as then at the fifth story, and that his drawing had been done from actual measurements, thus proving he had no access to the original plan,--circumstances strongly presumptive that the design was not his, but that of Luziano, who lived till the following year. The praise bestowed by him on the carved ornaments and decorations render it probable that they had been under his peculiar charge. There is no evidence as to the length of Baccio's stay at Urbino, but he is said to have obtained the privileges of citizenship, and to have built the church of S. Bernardino and the castle of Sinigaglia. [Footnote 121: _Carteggio_, I., pp. 274-6. The author has discussed the point in No. 86 of the _Kunstblatt_ for 1836.]