Mary, Queen of Scots (1542 – 1587), was Mary Stuart and Mary I of Scotland. She was Queen of Scotland from 14 December 1542 to 24 July 1567.

Mary was the daughter of King James V of Scotland. She came to the throne when only a baby and Scotland was ruled by nobles on her behalf, while she was brought up in France. In 1558, she married the Dauphin of France, who then became King Francis II in 1559, although he died a year later. Mary returned to Scotland and married her first cousin, Henry Stuart, also known as Lord Darnley. A few years later Darnley was found murdered.

It is possible that James Hepburn, 4th Earl of Bothwell, was responsible for the murder. He later married Mary. But this was not popular and the people of Scotland rose up against Mary and Mary was imprisoned in Loch Leven Castle. In 1567, she was forced to abdicate in favour of James, her one-year-old son. She tried to regain the throne but was unsuccessful. As a result, she was forced to flee to England, where Elizabeth I was queen. Elizabeth and Mary were cousins.This was later to be important because Elizabeth died without children and so Mary's son, James, was the next in line for the throne of England.

But for Mary, the problem was that she was related to Elizabeth and had previously claimed the throne of England for herself. She was also a Catholic. Elizabeth knew she was a threat to her own position, so she had her put under protective custody (effectively in jail) in a number of castles. But Mary continued to plot to overthrow Elizabeth even from within these castles and so, reluctantly, Elizabeth was forced to agree that she should be tried for treason so that she could be executed.