Thereafter men more used to ill than good tore me away from the sweet cloister; and God doth know what my life then became."--_Paradiso_ iii. Wicksteed's translation. It was at Poggio Imperiale, then called the Poggio dei Baroncelli, that a famous combat took place during the early days of the siege, in which Ludovico Martelli and Dante da Castiglione fought two Florentines who were serving in the imperial army, Giovanni Bandini and Bertino Aldobrandini. Both Martelli, the original challenger, and Aldobrandini were mortally wounded. Martelli's real motive in sending the challenge is said to have been that he and Bandini were rivals for the favours of a Florentine lady, Marietta de' Ricci. Among the many beautiful villas and gardens which stud the country beyond Poggio Imperiale, are Galileo's Tower, from which he made his astronomical observations, and the villa in which he was visited by Milton. Near Santa Margherita a Montici, to the east, is the villa in which the articles of capitulation were arranged by the Florentine ambassadors with Ferrante Gonzaga, commander of the Imperial troops, and Baccio Valori, commissary of the Pope. But already Malatesta had opened the Porta Romana and turned his artillery against the city which he had solemnly sworn to defend. Beyond the Porta Romana the road to the right of Poggio Imperiale leads to the valley of the Ema, above which the great Certosa rises on the hill of Montaguto. Shortly before reaching the monastery the Ema is crossed--an insignificant stream in which Cacciaguida (in _Paradiso_ xvi.) rather paradoxically regrets that Buondelmonte was not drowned on his way to Florence: "Joyous had many been who now are sad, had God committed thee unto the Ema the first time that thou camest to the city." The Certosa itself, that "huge battlemented convent-block over the little forky flashing Greve," as Browning calls it, was founded by Niccolò Acciaiuoli, the Florentine Grand Seneschal of Naples, in 1341; it is one of the finest of the later mediæval monasteries. Orcagna is said to have built one of the side chapels of the church, which contains a fine early Giottesque altarpiece; and in a kind of crypt there are noble tombs of the Acciaiuoli--one, the monument of the founder, being possibly by Orcagna, and one of the later ones ascribed (doubtfully) to Donatello. In the chapter-house are a Crucifixion by Mariotto Albertinelli, and the monument of Leonardo Buonafede by Francesco da San Gallo. From the convent and further up the valley, there are beautiful views. About three miles further on is the sanctuary and shrine of the Madonna dell' Impruneta, built for the miraculous image of the Madonna, which was carried down in procession to Florence in times of pestilence and danger. Savonarola especially had placed great faith in the miraculous powers of this image and these processions; and during the siege it remained in Florence ceremoniously guarded in the Duomo, a kind of mystic Palladium.