The case against Galileo was two cases. In 1616, after complaints about his advocacy of the Copernican system, a panel of theological consultants judged the propositions that the sun is the centre and immobile and that the earth moves to be philosophically absurd and, respectively, formally heretical and erroneous in faith. Galileo was not tried. He was admonished by Cardinal Bellarmine to abandon the opinion, and Copernicus's book was suspended from use until corrected.
The second proceeding followed his Dialogue Concerning the Two Chief World Systems of 1632, which had passed the censors and which presented the arguments as a conversation among three speakers. The defender of the older cosmology was given the name Simplicio and, worse, arguments the pope had personally pressed on Galileo. Urban VIII, previously a supporter, took it badly. In 1633 Galileo was tried, found vehemently suspect of heresy, required to abjure, and sentenced to imprisonment commuted to house arrest, which lasted the remaining nine years of his life.
He continued to work. His Discourses on the two new sciences, arguably his most important book, was written under house arrest and printed in the Netherlands beyond the reach of the prohibition. He went blind before it appeared.