The Borgo la Croce leads hence to the Porta alla Croce, in the very prosaic and modern Piazza Beccaria. This Porta alla Croce, the eastern gate of Florence in the third walls, was commenced by Arnolfo di Cambio in 1284; the frescoed Madonna in the lunette is by one of the later followers of Ghirlandaio. Through this gate, on October 6th 1308, Corso Donati fled from Florence, after his desperate attempt to hold the Piazza di San Piero Maggiore against the forces of the Signoria. Following the Via Aretina towards Rovezzano, we soon reach the remains of the Badia di San Salvi, where he was slain by his captors--as Dante makes his brother Forese darkly prophesy in the twenty-fourth canto of the _Purgatorio_. Four year later, in October 1312, the Emperor Henry VII. lay sick in the Abbey, while his army ineffectually besieged Florence. Nothing remains to remind us of that epoch, although the district is still called the Campo di Marte or Campo di Arrigo. We know from Leonardo Bruni that Dante, although he had urged the Emperor on to attack the city, did not join the imperial army like many of his fellow exiles had done: "so much reverence did he yet retain for his fatherland." In the old refectory of the Abbey is Andrea del Sarto's Last Supper, one of his most admirable frescoes, painted between 1525 and 1527, equally excellent in colour and design. "I know not," writes Vasari, "what to say of this _Cenacolo_ that would not be too little, seeing it to be such that all who behold it are struck with astonishment." When the siege was expected in 1529, and the defenders of the city were destroying everything in the suburbs which could give aid or cover to the enemy, a party of them broke down a wall in the convent and found themselves face to face with this picture. Lost in admiration, they built up a portion of what they had destroyed, in order that this last triumph of Florentine painting might be secure from the hand of war. * * * * *