Mary I (18 February 1516 – 17 November 1558), also known as Mary Tudor, was Queen of England and Queen of Ireland from 6 July 1553 (de jure) or 19 July 1558 (de facto) until her death.
Mary, the fourth and penultimate monarch of the Tudor dynasty, is remembered for returning England from Protestantism to Roman Catholicism. To this end, she had almost three hundred religious dissenters executed; as a consequence, she is often known as
Bloody Mary. Her religious policies, however, were in many cases reversed by her successor and half-sister, Elizabeth I (1558 – 1603). Mary Tudor was a cousin, once removed, of Mary, Queen of Scots, with whom she is often confused by those unfamiliar with British history.