Giorgio is when one party has obtained a superiority over the other, to bind the victor to the observance of its laws, which up to this time have not been changed; for as it possesses arms, money, and influence, they could not be altered without incurring the imminent risk of a dangerous rebellion. This establishment presents an instance of what in all the republics, either described or imagined by philosophers, has never been thought of; exhibiting within the same community, and among the same citizens, liberty and tyranny, integrity and corruption, justice and injustice; for this establishment preserves in the city many ancient and venerable customs; and should it happen (as in time it easily may) that the San Giorgio should have possession of the whole city, the republic will become more distinguished than that of Venice. Agostino Fregoso conceded Serezana to the San Giorgio, which readily accepted it, undertook its defense, put a fleet to sea, and sent forces to Pietra Santa to prevent all attempts of the Florentines, whose camp was in the immediate vicinity. The Florentines found it would be essentially necessary to gain possession of Pietra Santa, for without it the acquisition of Serezana lost much of its value, being situated between the latter place and Pisa; but they could not, consistently with the treaty, besiege it, unless the people of Pietra Santa, or its garrison, were to impede their acquisition of Serezana. To induce the enemy to do this, the Florentines sent from Pisa to the camp a quantity of provisions and military stores, accompanied by a very weak escort; that the people of Pietra Santa might have little cause for fear, and by the richness of the booty be tempted to the attack. The plan succeeded according to their expectation; for the inhabitants of Pietra Santa, attracted by the rich prize took possession of it. This gave legitimate occasion to the Florentines to undertake operations against them; so leaving Serezana they encamped before Pietra Santa, which was very populous, and made a gallant defense. The Florentines planted their artillery in the plain, and formed a rampart upon the hill, that they might also attack the place on that side. Jacopo Guicciardini was commissary of the army; and while the siege of Pietra Santa was going on, the Genoese took and burned the fortress of Vada, and, landing their forces, plundered the surrounding country. Biongianni Gianfigliazzi was sent against them, with a body of horse and foot, and checked their audacity, so that they pursued their depredations less boldly. The fleet continuing its efforts went to Livorno, and by pontoons and other means approached the new tower, playing their artillery upon it for several days, but being unable to make any impression they withdrew.