He returned to Florence in 1490 and began to preach about the end of the world. He had visions and prophecies which he said had come to him from God and the saints. Several disasters made his prophecies real. He spoke about the failing power of the ruling Medici family. Savonarola never tried to make war on the Roman Curia. He wanted to put an end to the sins of the popes who cared more about their riches and power than they did about God .