In 1558, Elizabeth finally became Queen of England and Ireland — though it was a dramatic path to the throne. Elizabeth’s half-brother, Edward I, was crowned King in 1547 when he was 9 years old. Edward, always a sickly boy, died at age 15. According to the preexisting succession plan, the throne was to go to Edward’s Protestant cousin Lady Jane Gray. Nine days after Jane took the throne, Elizabeth’s half-sister, Mary Tudor, had her executed and took the throne herself in what historian Anna Whitelock describes as “ an extraordinary coup d’etat. ” Mary enacted a violent campaign to turn England back into a Catholic country, earning herself the nickname Bloody Mary . Finally, after Mary’s death in 1558 at age 42 , the throne went to Elizabeth, who was Protestant. But even that was contested. Catholics believed Elizabeth the product of an unlawful marriage, and thus not a legitimate heir to the throne.