Now, while he was working with Bartoluccio and seeking to make progress in his profession, the plague came to Florence in the year 1400, as he himself relates in a book by his own hand wherein he discourses on the subject of art, which is now in the possession of the Reverend Maestro Cosimo Bartoli, a gentleman of Florence. To this plague were added civil discords and other troubles in the city, and he was forced to depart and to go in company with another painter to Romagna, where they painted for Signor Pandolfo Malatesti, in Rimini, an apartment and many other works, which were finished by them with diligence and to the satisfaction of that Lord, who, although still young, took great delight in matters of design. Meanwhile Lorenzo did not cease to study the arts of design, and to work in relief with wax, stucco, and other similar materials, knowing very well that these small reliefs are the drawing-exercises of sculptors, and that without such practice nothing can be brought by them to perfection. Now, when he had been no long time out of his own country, the pestilence ceased; wherefore the Signoria of Florence and the Guild of Merchants--since at that time sculpture had many excellent craftsmen, both foreign and Florentine--determined that there should be made, as it had been already discussed many times, the other two doors of S. Giovanni, a very ancient temple, indeed, the oldest in that city; and they ordained among themselves that instructions should be sent to all the masters who were held the best in Italy, to repair to Florence in order that their powers might be tested by a specimen scene in bronze, similar to one of those which Andrea Pisano had formerly made for the first door. Word of this determination was written to Lorenzo, who was working at Pesaro, by Bartoluccio, urging him to return to Florence in order to give a proof of his powers, and saying that this was an occasion to make himself known and to demonstrate his genius, not to mention that he might gain such profit that neither the one nor the other of them would ever again need to labour at making ear-rings.