How many years did Elizabeth I imprison Mary, Queen of Scots, before eventually executing her for alleged plots against the throne?

Mary, Queen of Scots, posed a significant threat to Elizabeth I's reign. As a Catholic with a strong claim to the English throne, Mary became a focal point for plots and rebellions against the Protestant Elizabeth. After being forced to abdicate the Scottish throne in 1567, Mary fled to England seeking protection from her cousin, Elizabeth. However, Elizabeth saw Mary as a dangerous rival. For nearly two decades, Mary was kept under house arrest in various castles and manors across England. During this time, several plots to assassinate Elizabeth and install Mary as queen were uncovered. The most significant was the Babington Plot in 1586, which provided concrete evidence of Mary's involvement in treason. This finally led to Elizabeth reluctantly signing Mary's death warrant. Mary was executed in 1587, after being imprisoned for 20 years. The length of her imprisonment reflects the delicate political situation Elizabeth navigated, balancing the need to protect her throne with the potential backlash from executing a fellow monarch.