When Michael Angelo saw how little his word was considered, and how the ruin of the city was certain, by the authority he had he caused a gate to be opened, and went out with two of his people, and betook himself to Venice.

And certainly this notion of a treachery was no fable; but he who arranged it judged that it would pass over with less disgrace if it was not discovered just then, as time would achieve the same result by his merely failing in his duty and hindering others who wished to do theirs.
The departure of Michael Angelo was the occasion of many rumours, and he fell into great disgrace with the governors.

All the same, he was recalled with many prayers, with appeals to his patriotism, and by those who urged that he must not abandon the responsibilities that he had taken upon himself, and that the matter was not at such an extremity as he had been given to understand, and many other things.

Persuaded by all this, and by the authority of the personages who wrote to him, but chiefly by his love for his country, after he had received a safe conduct for ten days before the day of his arrival in Florence, he returned, not without danger to his life.
XLIII.

Again in Florence the first thing he did was to protect the bell-tower of San Miniato, which was all broken by the continual cannonading of the enemy, and had become very dangerous to those within.
The method of defence was in this wise: a large number of mattresses, well filled with wool, were slung with stout cords from the top of the tower to the bottom, covering parts likely to be hit.