Mary, Queen of Scots, was placed on trial under charges of conspiracy against Queen Elizabeth I due to her involvement in the Babington Plot, which aimed to assassinate Elizabeth and elevate Mary to the English throne. The Babington Plot unfolded in 1586, driven by Catholic dissatisfaction with Elizabeth's Protestant rule and Mary's status as a legitimate heir in the eyes of many Catholics. The trial was held at Fotheringhay Castle, where Mary defended herself by arguing about her royal rights and her lack of the intention to harm Elizabeth. Despite her appeals, the trial was seen more as a formality than a true legal process.

The trial drew significant public and political interest and was emblematic of the struggle between Catholics and Protestants during this period. The secret correspondence between Mary and the conspirators, along with her complicity in the plot, was presented by Elizabeth's council as undeniable evidence against her. Despite her arguments and claims of innocence, the political climate and the need for Elizabeth to secure her reign weighed heavily against Mary. After a brief deliberation, Mary was found guilty, leading to a sentence of death.

Mary's trial and subsequent execution shaped the political landscape of England and Scotland, further entrenching the divide between Catholics and Protestants. It also solidified Elizabeth I's power and led to a series of brutal policies against suspected Catholic conspirators. The ramifications of the trial extended beyond Mary herself, impacting the historical relationship between England and Scotland and contributing to ongoing conflicts in the British Isles.