Your typical academic

It was not the first time, nor was it to be the last, that Bruno's controversial views coupled with his abrasive sarcasm lost him the support of his friends. In October 1585, after the French embassy in London was attacked by a mob, he returned to Paris, finding a tense political situation. His 120 theses against Aristotelian natural science and his pamphlets against the mathematician Fabrizio Mordente soon put him in ill favor. In 1586, following a violent quarrel about Mordente's invention, "the differential compass," he left France for Germany.

In Germany he failed to obtain a teaching position at Marburg, but was granted permission to teach at Wittenberg, where he lectured on Aristotle for two years. However, with a change of intellectual climate there, he was no longer welcome, and went in 1588 to Prague, where he obtained 300 taler from Rudolf II, but no teaching position. He went on to serve briefly as a professor in Helmstedt, but had to flee again when he was excommunicated by the Lutherans. In 1591, he received an invitation to Venice, and also heard of a vacant chair in mathematics at the University of Padua. Apparently believing that the Inquisition might have lost some of its impetus, he returned to Italy.

He went first to Padua, where he taught briefly, and applied unsuccessfully for the chair of mathematics, which was assigned instead to Galileo Galilei one year later. Bruno accepted Mocenigo's invitation and moved to Venice in March 1592. When Bruno announced his plan to leave Venice to his host, the latter, who was unhappy with the teachings he had received and had apparently developed a personal rancour towards Bruno, denounced him to the Venetian Inquisition, which had Bruno arrested on May 22, 1592. On February 17, 1600 in the Campo de' Fiori, a central Roman market square, "his tongue imprisoned because of his wicked words" he was burned at the stake.