Niccola was present when the foundations of the Duomo of Siena were laid, and he designed the Church of S. Giovanni in that city. He went back to Florence in the year of the return of the Guelphs, and designed the church of S. Trinita, and the women's convent at Faenza, pulled down in recent years to make the citadel. Being subsequently summoned to Naples, and not wishing to abandon his enterprises in Tuscany, he sent thither his pupil Maglione, sculptor and architect, who in the time of Conrad afterwards built the church of S. Lorenzo at Naples, finished a part of the Vescorado, and made some tombs there, in which he closely imitated the manner of his master, Niccola. In the meantime Niccola went to Volterra, in the year that the people of that place came under the dominion of the Florentines (1254), in response to a summons, because they wished him to enlarge their Duomo, which was small; and although it was very irregular, he improved its appearance, and made it more magnificent than it was originally. Then at length he returned to Pisa and made the marble pulpit of S. Giovanni, devoting all his skill to it, so that he might leave a memory of himself in his native place. Among other things in it he carved the Last Judgment, filling it with a number of figures, and if they are not perfectly designed they are at any rate executed with patience and diligence, as may be seen; and because he considered that he had completed a work which was worthy of praise, as indeed he had, he carved the following lines at the foot: "Anno milleno bis centum bisque trideno. Hoc opus insigne sculpsit Nicola Pisanus."