Galileo's Heliocentrism Controversy (1620s, before the 1633 trial)

Timeline

1. 1620–1622Florence · TuscanyUnder the patronage of the Grand Duke of Tuscany, Galileo, after the 1616 papal order, still treated tides, sunspots, and comets mathematically and physically, covertly advancing mechanical arguments for the Copernican system and exchanging polemics with scholastic scholars over the nature of celestial bodies.
2. 1623–1624Rome · LazioIn 1623 Galileo published Il Saggiatore expounding atomism and scientific method, and that same year his old friend Maffeo Barberini ascended as Urban VIII. In 1624 Galileo went to Rome, received six audiences, and was permitted to discuss heliocentrism but not to 'hold or defend' it; conservative theologians had begun collecting material against him.
3. 1625–1630Italian Peninsula · ItalyIn the later 1620s Galileo wrote the Dialogue Concerning the Two Chief World Systems, comparing geocentric and heliocentric systems in dialogue form; the Inquisition and Jesuit scholars watched his intentions warily, and Urban VIII's manner of citing the tidal argument later became grounds for the trial; by 1630 the controversy was irreconcilable.