This was the gruesome faith the Saint Inquisition inflicted heretics. Giordano Bruno refused until the end to forswear the fundamental principles of his theories.
In his abundant literature (from “Cena de le ceneri” to “De la causa, principio et uno”, to “De l’infinito, universo e mondi” up to “De Magia”), the philosopher claimed that the universe was infinite, provided with an intelligence, filled with solar systems and even other life forms, and that it was not created by God, even though it was his direct and immediate manifestation.
Bruno even refuted the idea of the soul's immortality and embraced the Copernican theories on the motion of the Earth.
On the 8 of February 1600, he answered the judge that was reading him his death sentence: “You probably shiver more, pronouncing this sentence, than I listening to it”.
Watch the Sentence scene from Giuliano Montaldo's movie Giordano Bruno (1973) an Italian biographical-drama film directed chronicling the last years of life of the philosopher Giordano Bruno from 1592 to his killing in 1600, superbly interpreted by Gian Maria Volonté.