 In 1553 , Calvin 's front man , Guillaume de Trie , sent letters trying to address the French Inquisition to Servetus . Calling him a " Spanish @-@ Portuguese " , suspecting and accusing him of his recently proved Jewish converso origin . De Trie wrote down that " his proper name is Michael Servetus , but he currently calls himself Villeneuve , practising medicine . He stayed for some time in Lyon , and now he is living in Vienne . " When the inquisitor @-@ general of France learned that Servetus was hiding in Vienne , according to Calvin under an assumed name , he contacted Cardinal François de Tournon , the secretary of the archbishop of Lyon , to take up the matter . Servetus was arrested and taken in for questioning . His letters to Calvin were presented as evidence of heresy , but he denied having written them , and later said he was not sure it was his handwriting . He said , after swearing before the holy gospel , that " he was Michel De Villeneuve Doctor in Medicine about 42 years old , native of Tudela of the kingdom of Navarre , a city under the obedience to the Emperor " . The following day he said : " .. although he was not Servetus he assumed the person of <unk> for debating with Calvin " . He managed to escape from prison , and the Catholic authorities sentenced him in absentia to death by slow burning . 
