Giordano Bruno (1548 – February 17, 1600), born Filippo Bruno, was an Italian Dominican friar, philosopher, mathematician and astronomer. His cosmological theories went beyond the Copernican model in proposing that the Sun was essentially astar, and moreover, that the universe contained an infinite number of inhabited worlds populated by other intelligent beings.He was burned at the stake by civil authorities in 1600 after the Roman Inquisition found him guilty of heresy for his pantheismand turned him over to the state, which at that time considered heresy illegal. After his death he gained considerable fame; in the 19th and early 20th centuries, commentators focusing on his astronomical beliefs regarded him as a martyr for free thought and modern scientific ideas.

Recent assessments suggest that Bruno's ideas about the universe played a smaller role in his trial than his pantheist beliefs, which differed from the interpretations and scope of God held by the Catholic Church.In addition to his cosmological writings, Bruno also wrote extensive works on the art of memory, a loosely organized group of mnemonic techniques and principles. More recent assessments, beginning with the pioneering work of Frances Yates, suggest that Bruno was deeply influenced by the astronomical facts of the universe inherited from Arab astrology, Neoplatonism and Renaissance Hermeticism. Other recent studies of Bruno have focused on his qualitative approach to mathematics and his application of the spatial paradigms of geometry to language.