21 Sept is the birthday of Girolamo Savonarola, born in Ferrara (1452). When he was 22, he left off studying medicine to join an order of Dominican monks, and he developed a reputation for his prophetic preaching. He settled in Florence in 1490, where he became the scourge of the Medici family, who were then in power. Savonarola's speeches against tyranny made him popular with the people, and the rule of the Medicis came to an end not long after the death of their leader, Lorenzo. Savonarola soon filled the void, setting up a republic and continuing to preach against the corruption of the Catholic Church.
As the head of the Church, the notoriously corrupt Pope Alexander VI was displeased by Savonarola's influence. Alexander tried first to trap him by luring him to Rome, but Savonarola saw through the scheme and refused, claiming illness. The pontiff threatened him with excommunication, and then tempted him with a Cardinalship, to which the reformer replied, "A red hat? I want a hat of blood." Eventually, he got his wish: in 1498, he was arrested, tortured, and executed by hanging and then burning. His ashes were scattered in the Arno River.
What are the best sightseeing spots in Florence and Ferrara for him and the Medicis?
https://www.britannica.com/biography/Girolamo-Savonarola
Two interesting tidbits -- he was never formally beatified even though he's credited with several miracles and was venerated widely, and he was contemporary with Leonardo da Vinci but there's only speculation about whether they met.