Babington plot was a Roman Catholic plot to assassinate Elizabeth I of England and to make Mary, Queen of Scots, the queen of England. Early in 1586, Anthony Babington and several other Catholics began to plan Elizabeth’s assassination. Babington sent Mary an account of his plans, to which she replied favorably. But through his spies, Sir Francis Walsingham, Elizabeth’s secretary of state, learned of the plot (see Walsingham, Sir Francis). Babington and the other conspirators were captured and executed for treason. Mary’s involvement led to her own trial and execution. See also Elizabeth I; Mary, Queen of Scots.