Protestants became even more fearful when his wife , Mary of Modena , gave birth to a son -- James Francis Edward -- in June 1688 . They were fearful because the son would , unlike Mary and Anne , be raised a Roman Catholic . Alarm amongst Protestants increased when his wife , Mary of Modena , gave birth to a sonâ '' James Francis Edwardâ '' in June 1688 , for the son would , unlike Mary and Anne , be raised a Roman Catholic .