This Monte di San Francesco e di San Miniato overlooks the whole city, and Florence lay at the mercy of whoever got possession of it. Varchi in his history apologises for those architects who built the walls of the city by reminding us that, in their days, artillery was not even dreamed of, much less invented. Michelangelo armed the campanile of San Miniato, against which the fiercest fire of the imperialists was directed, and erected bastions covering the hill, enclosing it, as it were, within the walls up from the Porta San Miniato and down again to the Porta San Niccolò. It was intrusted to the guard of Stefano Colonna, who finally joined Malatesta Baglioni in betraying the city. Some bits of Michelangelo's work remain near the Basilica, which itself is one of the most venerable edifices of the kind in Tuscany; the earliest Florentine Christians are said to have met here in the woods, during the reign of Nero, and here Saint Miniatus, according to tradition the son of an Armenian king, lived in his hermitage until martyred by Decius outside the present Porta alla Croce. In the days of Gregory the Great, San Frediano of Lucca came every year with his clergy to worship the relics of Miniatus; a basilica already stood here in the time of Charlemagne; and the present edifice is said to have been begun in 1013 by the Bishop Alibrando, with the aid of the Emperor St Henry and his wife Cunegunda. It was held by the Benedictines, first the black monks and then the Olivetans who took it over from Gregory XI. in 1373. The new Bishops of Florence, the first time they set foot out of the city, came here to sing Mass. In 1553 the monastery was suppressed by Duke Cosimo I., and turned into a fortress.