Heated words passed on both sides, and the Pope had to reduce the men to silence.

Before long he brought a plan for the fortification of the whole Borgo, which opened the eyes of those in power to the scheme which was finally adopted.
Owing to changes he suggested, the great gate of Santo Spirito, designed by Sangallo and nearly finished, was left incomplete." It is not clear what changes were introduced into Sangallo's scheme.
They certainly involved drawing the line of defence much closer to the city than he intended.

This approved itself to Pier Luigi Farnese, then Duke of Castro, who presided over the meetings of the military committee.

It was customary in carrying out the works of fortification to associate a practical engineer with the architect who provided designs; and one of these men, Gian Francesco Montemellino, a trusted servant of the Farnesi, strongly supported the alteration.

That Michelangelo agreed with Montemellino, and felt that they could work together, appears from a letter addressed to the Castellano of S.
Angelo.