Mary I was the only surviving child of King Henry VIII of England and his first wife Catherine of Aragon; she was declared illegitimate in 1533 when Henry divorced Catherine. As her father racked up five more wives and two more children, Mary was in and out of favor at court, but she was eventually restored to the line of succession to the throne, next after her younger half-brother Edward VI. However, in 1549 she refused to comply with the Act of Uniformity which required all houses to use the new Anglican Book of Common Prayer, continuing to attend Catholic mass. Her religion worried English Protestants, and when Edward died in 1553, the woman he named his heir on his deathbed, Lady Jane Grey was queen for nine days, before Mary was able to gather the support of the nobles and the people of England to depose Jane.

Mary fulfilled Protestants' worries and did her best to restore the old Catholic ways to the country; she was nicknamed "Bloody Mary" for her persecutions of Protestants. She married Prince Philip of Spain and had him named King, equal with her, wanting to have children who would replace her Protestant younger sister Elizabeth as heirs to the throne. Mary felt passionately about Philip, but he was 11 years younger than her 38 years and did not find her attractive at all; he spent as much time as he could in Spain. Though Mary believed herself to be pregnant on several occasions, she never did have any children.

Mary and Philip joined Spain in 1557 in a war with France, but managed to lose the city of Calais, the only remaining English possession on the European mainland. After that Philip left for Spain permanently, and Mary died of influenza on 17 November 1558. She was succeeded by her half-sister Elizabeth I.