In her York prison Margaret Clitherow practised for her execution. She stripped naked and put on a crude linen shift she had made, unstitched at the sides. Then she lay flat on the stones. The next day, 25 March 1586, she lay down again, this time with weights laid over her, and was crushed to death. In 1970 the Catholic Church declared her a saint. But as Peter Lake and Michael Questier reveal, her fate was not only a consequence of Protestant persecution, but of a bitter ideological war between Catholics.