Mary I of England

Mary was Henry VIII's only surviving child with Catherine of Aragon. When Henry annulled the marriage in 1533, she was declared illegitimate and cut from succession - restored only by act of Parliament a decade later. Her half-brother Edward VI took the throne at nine in 1547 and pushed England further Protestant. Dying at fifteen in 1553, he tried to skip over Mary entirely, and politicians briefly proclaimed their cousin Lady Jane Grey queen instead. Mary raised a force in East Anglia and deposed Jane within days, becoming England's first undisputed queen regnant. She married Philip of Spain in 1554, a widely unpopular match, and spent her reign trying to restore Catholicism and reclaim Church property seized under her father and brother. Parliament blocked much of it. She died in November 1558, and her half-sister Elizabeth immediately undid everything she'd accomplished.