On December 7, 1542, at Linlithgow Palace, Marie of Guise, wife of James V of Scotland, gave birth to Mary Stuart. On December 13, her father, James died, making the six-day-old Mary the Queen of Scotland. From very early on in her life, Mary was the subject of plots by both the pro-English and pro-French forces in Scotland who wanted to gain control of the throne through her. Later, when her mother became Queen Regent of France, Mary was sent there to live as part of the French Royalty.

While in France Mary eventually married, in April of 1558, Dauphin Francis. She later became the Queen of France, as well as Scotland, when Francis succeeded his father to become King Francis II in July 1559. In addition, Mary was also recognized as the true Queen of England by many Roman Catholics who believed her claim to the throne was stronger than that of the Protestant (and cousin of Mary) Elizabeth I. Mary was forced to return to Scotland however when her husband Francis II died after only a 17-month reign.

Mary's ship landed in Leith on August 19, 1561, and she almost immediately followed the suggestions of her advisors by recognizing the Reformed Presbyterian church. This act did not sit very well with the Catholics who thought she should be more zealous in the support of their cause, and the Protestants, led by John Knox, were naturally suspicious of her motives because of her Catholicism. She spent several years trying to placate the Protestants, but all this became undone when, on 29th July 1565, she married her first cousin Henry Stewart, Lord Darnley.

This marriage caused great outrage among the Protestants, some of whom staged a rebellion, which was quickly crushed by Mary. Things started to go downhill for her from this point; the rebellion caused her to withdraw some of her support from the Reformed Church and her marriage to Lord Darnley began to sour. The culmination, however, came on March 9, 1566, when a group of Protestants, under the instruction of Darnley, forced Mary to watch as they murdered her Italian Secretary David Rizzio. Many of the Protestant lords believed that Rizzio had too much influence over Mary, and also suspected him of being a papal spy.

The murder, which occurred while Mary was 6 months pregnant, left her alienated from Darnley and her supporters, and also caused her to befriend James Hepburn, Earl of Bothwell. In Edinburgh Castle on June 19, 1566, she gave birth to a son, James, and soon afterwards began looking for ways to end her marriage with Darnley in favour of Bothwell. Darnley was murdered on the10th February, 1567 at Kirk o' Field under mysterious circumstances that are still unexplained to this day. Bothwell was believed to have committed, or at least instigated, the killing, but was acquitted of because there was no proof.

Bothwell, shortly after obtaining a divorce from his wife, was wed with Mary according to the Protestant rite (there is some belief among historians that Bothwell kidnapped Mary and then married her against her will). This estranged Mary from even some of her most loyal supporters, causing them and many of the nobles to confront Mary and her new husband at Carberry. Bothwell fled while she was forced to surrender and was imprisoned at Lochleven Castle. Then, on July 24, 1567, she was forced to abdicate, making her son James the King, but she later escaped with the aid of a few of her remaining allies.

After her escape, Mary quickly raised an army, but was soundly beaten in battle at Langside on May 13, 1568 by Protestant forces. Her army and support gone, Mary was forced to flee to England to beg for aid from Elizabeth, the Queen and her cousin. Rather than helping her however, Elizabeth had Mary imprisoned, where she spent the remainder of her life. During her incarceration, many Roman Catholic plots to remove the Protestant Queen from power revolved around Mary, but were thwarted by English agents.

The last of these schemes, known as the Babington plot, was formulated by English agents as a trap for Mary and called for the assassination of Elizabeth. The trap worked; Mary was found guilty of complicity and her beheading was ordered by Elizabeth. The order was carried out on February 8, 1587, at Fotheringhay Castle. Her first burial place was at Peterborough, but her remains were later moved to Westminster Abbey by her son, James VI of Scotland (also known as James I of England), when he ascended to the English throne in 1603 following Elizabeth's death.