1587 Feb 8, Mary Stuart, Queen of Scots (1560-67), was beheaded at age 44 in Fotheringhay Castle for her alleged part in the conspiracy to usurp Elizabeth I. In 2004 Jane Dunn authored “Elizabeth and Mary: Cousins, Rivals, and Queens.” In 2006 studies identified an oil painting of Mary as the only one made of Mary as queen.
1952 Feb 8, Elizabeth was formally proclaimed Queen of England following the Feb 6 death of her father, King George VI. Elizabeth was crowned Jun 2.
Source: Timelines of history