During her imprisonment at Lochleven Castle in Scotland, Mary Queen of Scots is forced to abdicate in favor of her one-year-old son, later crowned King James VI of Scotland.

In 1542, while just six days old, Mary ascended to the Scottish throne upon the death of her father, King James V. Her mother sent her to be raised in the French court, and in 1558 she married the French dauphin, who became King Francis II of France in 1559 but died the following year. After Francis’ death, Mary returned to Scotland to assume her designated role as the country’s monarch.

In 1565, she married her English cousin Lord Darnley in order to reinforce her claim of succession to the English throne after Elizabeth’s death. In 1567, Darnley was mysteriously killed in an explosion at Kirk o’ Field, and Mary’s lover, the Earl of Bothwell, was the key suspect. Although Bothwell was acquitted of the charge, his marriage to Mary in the same year enraged the nobility, and Bothwell and Mary were imprisoned. Mary was held on the tiny island of Loch Leven, where she was forced to abdicate in favor of her son by Darnley, James.

In 1568, she escaped from captivity and raised a substantial army but was defeated and fled to England. Queen Elizabeth initially welcomed Mary but was soon forced to put her friend under house arrest after Mary became the focus of various English Catholic and Spanish plots to overthrow Elizabeth. Nineteen years later, in 1586, a major plot to murder Elizabeth was reported, and Mary was brought to trial. She was convicted for complicity and sentenced to death.

READ MORE: The Wildly Different Childhoods of Elizabeth I and Mary Queen of Scots

On February 8, 1587, Mary Queen of Scots was beheaded for treason. Her son, King James VI of Scotland, calmly accepted his mother’s execution, and upon Queen Elizabeth’s death in 1603 he became king of England, Scotland, and Ireland.