The author draws on public records, ambassadorial dispatches, private letters, and contemporary chronicles to present a documentary biography of Mary I, tracing her life from birth and childhood through courtly conflicts, religious controversies, the controversial marriage alliance, the persecution of Protestants, foreign wars, and final years. Emphasis falls on closely quoted primary sources and diplomatic reports from European archives, with chapters arranged chronologically and supplemented by illustrations and an appendix. The work aims to reassess a contested reputation by restoring the period's perspective and reproducing contemporaries' voices to illuminate political, religious, and personal complexities.