Agostino, then, being engaged in working with Giovanni on the marble panel of the high-altar in the Vescovado of Arezzo, whereof there has been mention above, contrived to bring there the said Agnolo, his brother, who acquitted himself in this work in such a manner that when it was finished he was found to have equalled Agostino in the excellence of his art. Which circumstance, becoming known to Giovanni, was the reason that after this work he made use of both one and the other in many other works of his that he wrought in Pistola, in Pisa, and in other places. And seeing that he applied himself not only to sculpture but to architecture as well, no long time passed before, under the rule of the Nine in Siena, Agostino made the design of their Palace in Malborghetto, which was in the year 1308. In the making of this he acquired so great a name in his country, that, returning to Siena after the death of Giovanni, they were made, both one and the other, architects to the State; wherefore afterwards, in the year 1317, there was made under their direction the front of the Duomo that faces towards the north, and in the year 1321, with the design of the same men, there was begun the construction of the Porta Romana in that manner wherein it stands to-day, and it was finished in the year 1326; which gate was first called Porta S. Martino. They rebuilt, also, the Porta a Tufi, which at first was called Porta di S. Agata all'Arco. In the same year, with the design of the same Agostino and Agnolo, there was begun the Church and Convent of S. Francesco in the presence of Cardinal di Gaeta, Apostolic Legate. No long time after, by the action of some of the Tolomei who were living as exiles at Orvieto, Agostino and Agnolo were summoned to make certain sculptures for the work of S. Maria in that city; wherefore, going there, they carved some prophets in marble which are now, in comparison with the other statues in that facade, the finest and best proportioned in that so greatly renowned work.