In December 1585, Gilbert Clifford was arrested in Sussex. While being interviewed, Clifford confessed that he had been involved in a Catholic plot to overthrow Elizabeth I. The man in charge of protecting Elizabeth was Francis Walsingham. He offered to release Clifford if he was willing to work as a double-agent. Clifford agreed and went to his contact in the French embassy telling him that he knew how to smuggle letters to and from Mary Stuart. He explained that every week a barrel of beer was sent from Burton to where Mary was imprisoned. Clifford arranged to have letters placed in a waterproof package inside the stopper of the barrel.
Another double-agent, Thomas Philips, who was inside the prison, told Mary how she would be receiving letters in her beer barrel. However, before they were placed inside the beer barrel, they were read by Walsingham. More importantly, Francis Walsingham was also able to read the letters that Mary sent to her Catholic friends in France and Spain. In these letters Mary explained how she wanted France and Spain to help her become queen by invading England.
Walsingham allowed the letters to continue to be sent because he wanted to discover who else was involved in this plot to overthrow Elizabeth. Eventually, on 25 June 1586, Mary wrote a letter to Anthony Babington. In his reply, Babington told Mary that he and a group of six friends were planning to murder Elizabeth.
Walsingham was now ready to act. Babington was arrested and his home was searched for documents that would provide evidence against him. When interviewed, Babington made a confession in which he admitted that Mary had written a letter supporting the plot.
Anthony Babington and six others were executed for high treason on 18 September, 1586. An attempt to kill the monarch was the most serious crime in England and the punishment was to be hung, drawn and quartered. The men were tied face downwards on a hurdle drawn by horses. They were then dragged through the streets of London. At Tyburn they were hung for a short period. After being revived the men had their intestines cut out.
At the execution the crowd complained about the agonies the men had to suffer before they died. When she heard this Elizabeth gave instructions that the rest of the conspirators due to be executed the next day should be dead before they were cut down.
Elizabeth was also against Mary Stuart being executed for her part in the plot, and for six weeks refused to sign her death warrant. Walsingham and Parliament insisted that Mary should die. On 8 February, 1587 Mary was beheaded. Afterwards, Elizabeth claimed that she had not given permission for Mary to be executed. As a result, Davidson, the man responsible for the execution, was fined £6,000 and imprisoned in the Tower of London.
We... will undertake the delivery of your royal persons from the hands of your enemies... For the dispatch of the usurper (Elizabeth)... six noble gentlemen, who, for the zeal they have to the Catholic cause... will undertake that tragical execution.
When all is ready, the six gentlemen must be set to work, and.... when it is accomplished, I may be in some way got away from here... then we will await foreign assistance.
There is a letter from the Scottish Queen, that hath wrought tears... the delay (in executing Mary) is too dangerous.
While Mary was in England, plot after plot was made against Elizabeth by Mary's friends, and by men who looked to her as their rightful queen. Whether Mary knew of these plots is uncertain... Letters were found... but there were many who said then, and many who still believe, that these letters were forgeries - that is to say, that they were written by Mary's enemies for the purpose of making people believe she was guilty.
The executioners, kneeling, desired her Grace to forgive them her death: who answered, "I forgive you with all my heart, for now, I hope, you shall make an end to all my troubles."... Then she, lying very still upon the block, one of the executioners holding her slightly with one of his hands, she endured two strokes of the axe... Her lips stirred up and down a quarter of an hour after her head was cut off.