In 1606 Henry Garnet, provincial of the English Jesuits and purported co-conspirator in the Gunpowder Plot against James I, was executed at St. Paul’s Cathedral in London. Following his death, accounts of miracles occurring at his execution began to spread throughout England, including an account of a relic bearing his miraculous image. While Catholic writers promoted these accounts as evidence of Garnet’s innocence, Protestant contemporaries argued that Garnet was an illegitimate martyr and that his commemoration was evidence of Catholic support for regicide. This article demonstrates how London Protestant writers and publishers utilized anti-hagiographical arguments to intervene in attempts to promote Garnet’s sainthood, counter claims about the veracity of his relic, and shape his legacy in the decades following his execution.