Elizabeth welcomed Mary to England and refused to turn her over to the Scottish government. She then persuaded both parties to present their cases before an English tribunal, first at York and then at Westminster (1568–69). At the inquiry Murray presented the famous Casket Letters, poems and letters allegedly written by Mary to Bothwell that supposedly proved her share in the plot against Darnley. Mary insisted that parts of the letters were forgeries, and the available evidence suggests that this was the case. In any event, the judgment was that the abdication and Murray's regency were legal, but that Mary's complicity in Darnley's murder was unproven (as it remains).
Mary became a prisoner of the English government, living for the next 16 years in the lenient custody of the earl of Shrewsbury and then under the stricter surveillance of Sir Amias Paulet. She schemed ceaselessly to regain her liberty and was party to a succession of plots that would have raised her to the English throne with the help of a Catholic uprising and a Spanish invasion. The uncovering of such plots, real and alleged, some involving important English nobles in schemes to murder Elizabeth, led Parliament to clamor for Mary's execution.
Elizabeth refused to take action until the discovery by Sir Francis Walsingham of a plot led by Anthony Babington. The evidence implicated Mary, and she was arrested and taken to Fotheringay Castle. At her trial Mary defended herself with eloquence and dignity, but there was no doubt of her complicity. Elizabeth hesitated to sign the death warrant, but after assurance from James in Scotland that he would not interfere, and under great pressure from Lord Burghley and her other counselors, she reluctantly consented. Mary was beheaded at Fotheringay on Feb. 8, 1587.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.