Anthony Babington was a wealthy young Catholic with a great admiration for Mary Queen of Scots. During a period spent abroad he came into contact with the network of Catholic plotters working for Mary's release and Elizabeth's overthrow or assassination.

In May 1586, he was told of a plot against Elizabeth's life. There was to be a Catholic rising in England supported by a foreign invasion. Elizabeth was to be murdered and Mary Queen of Scots was to be released and put on to the English throne. Babington's role was to carry messages between the plotters and Mary.

Fearing to commit himself, Babington decided to flee the country and applied to Walsingham for a permit to travel abroad (he was under suspicion as a result of earlier attempts to contact the Scottish Queen). Instead of granting him permission, Walsingham sent one of his own agents, Robert Poley, to pose as a fellow plotter and gain Babington's trust.

Babington revealed all the details of the plot to Poley, including the intention to murder Elizabeth. All Walsingham now needed was proof. He therefore allowed the exchanging of letters to go on, without either Babington or Mary suspecting anything.

Finally, on 29th July, he had the proof he needed of Mary's treason - a letter to Babington agreeing to all the details of the plot, including the intention to murder Elizabeth. This brought Mary to the block and Babington to the scaffold, where he was hanged and then quartered.