that which he
acquired by himself and that which Genga taught him, he became a good
architect, and particularly in the matter of fortifications and other
things relating to war.

Then, in the year 1541, his wife died, leaving him two boys; and he
remained until 1543 without coming to any further resolution about his
life. At that time, in the month of September, there appeared in San
Marino one Signor Gustamante, a Spaniard, sent by his Imperial Majesty
to that Republic on some affairs. Giovan Battista was recognized by
him as an excellent architect, and at his instance he entered not
long afterwards into the service of the most illustrious Lord Duke
Cosimo, as engineer. And thus, having arrived in Florence, his
Excellency made use of him for all the fortifications of his dominion,
according to the necessities that arose every day; and, among other
things, the fortress of the city of Pistoia having been begun many
years before, San Marino, by the desire of the Duke, completely
finished it, with great credit to himself, although it is no great
work. Then, under the direction of the same architect, a very strong
bastion was built at Pisa. Wherefore, his method of work pleasing the
Duke, his Excellency caused him to construct--where, as has been
related, there had been built on the hill of S. Miniato, without
Florence, the wall that curves from the Porta S. Niccolo to the Porta
S. Miniato--the fortification that encloses a gate by means of two
bastions, and guards the Church and Monastery of S. Miniato; making on
the summit of that hill a fortress that dominates the whole city and
looks on the outer side towards the east and the south, a work that
was vastly extolled. The same Giovan Battista made many designs and
ground-plans of various fortifications for places in the states of his
Excellency, and also various rough models in clay, which are in the
possession of the Lord Duke. And since San Marino was a man of fine
genius and very studious, he wrote a little book on the methods of
fortifications; which work, a beautiful and useful one, is now in the
possession of Messer Bernardo Puccini, a gentleman of Florence, who
learned many things with regard to the matters of architecture and
fortification from San Marino, who was much his friend.

Giovan Battista, after having designed in the year 1554 many bastions
that were to be built round the walls of the city of Florence, some of
which were begun in earth, went with the mo