Technically, Elizabeth Windsor became the Queen of England as soon as her father, King George VI died on February 2 of 1952. But until her actual coronation – a lengthy religious ceremony held in Westminster Abbey – took place more than a year later.
This was necessary for political and religious purposes – without this apparently meaningless ceremony, the divine right of kings (well, queens in this case), would fall by the wayside, and that would just be unacceptable. Elizabeth has now been the Queen long enough to have become the third longest reigning English monarch.
Mary, Queen of Scots (or Marie Stuart, as she is known in France), was the daughter and heir of James V of Scotland. She was also a claimant to the throne of her cousin, Elizabeth I of England. The two women were frequently at odds, both politically and in religious matters – Mary was a Catholic, ELizabeth a Protestant, and the situation between the two faiths in the British Isles at that time was as divisise and violent as it remains in Northern Island.
In 1567, the Scottish nobility turned on Mary, and she was forced to abdicate in favour of her son, James (who was only a year old at the time, but became James VI just the same). She was imprisoned in Scotland, but in early May she escaped and raised a small army. Meeting with defeat in this revolt, she fled to England, seeking the aid of her cousin. Unfortunately, Mary had misjudged her cousin’s mood, and Elizabeth quickly had her thrown into prison, and eventually executed.
Later, Elizabeth herself died without issue, and James IV of Scotland became James I of England, unifying the two kingdoms.