Confirming Wiki,
"The grounds on which Bruno was sentenced are unknown, for the processo, or official document containing the sentence, is irretrievably lost. It formed part of a mass of archives that were transported, by order of Napoleon, from Rome to Paris, where they were pulped. From the reports of the interrogations, it is, however, possible to form an idea of the drift of the case against him. To his major theological heresy, the denial of the divinity of the Second Person of the Trinity, was added suspicion of diabolical magical practices. It was probably mainly as a magician that Bruno was burned, and as the propagator throughout Europe of some mysterious magicoreligious movement. This movement may have been in the nature of a secret Hermetic sect, and may be connected with the origins of Rosicrucianism or of Freemasonry. If any philosophical or cosmological points were included in his condemnation, these would have been inextricably bound up with his "Egyptianism."

The legend that the nineteenth century built around Bruno as the hero who, unlike Galileo, refused to retract his belief that the earth moves is entirely without foundation."

This article is based on my books, Giordano Bruno and the Hermetic Tradition (Chicago, 1964), and The Art of Memory (Chicago, 1966). On Bruno, Gilbert, and Bacon, see my essay "The Hermetic Tradition in Renaissance Science," in Art, Science, and History in the Renaissance, Charles S. Singleton, ed. (Baltimore, 1968), pp. 255–274.
Frances A. Yates.
http://www.encyclopedia.com/topic/Giordano_Bruno.aspx