He was one of the commanders appointed by Cardinal Cisneros, then regent of the kingdom, to establish an armed body that would exclusively serve the crown.
Juan Bravo continued to lead the Segovia militia throughout the Castilian War of the Communities of Castile and managed the defence against the kingdom's soldiers.
He was captured, and the day after the battle, on April 24, 1521, he was beheaded for treason along with two other rebel leaders, in Villar de los Commonros in Spain.
The families of Catalina del Rio, of Maria Coronel as well as his political supporters tried to turn the funeral into a solemn tribute to someone who is considered the protector of the community.
The royal authorities found it difficult to contain the angry reaction of the crowd, and finally suppressed it with a heavy hand.