By establishing a system whereby Mary's personal letters were carried in and out of Chartley (her current residence) hidden in a beer barrel, Walsingham was able to intercept and decode her correspondence. The relatively simple code used by Mary was quickly deciphered, and translations were provided for Elizabeth.

Who uncovered the Babington Plot?

The plot was discovered by Elizabeth's spymaster Sir Francis Walsingham and used to entrap Mary for the purpose of removing her as a claimant to the English throne. The chief conspirators were Anthony Babington and John Ballard.

Was the Babington Plot a threat?

The Babington Plot was a 1586 conspiracy to kill the Protestant Queen Elizabeth I and replace her with her Catholic cousin, Mary, Queen of Scots. ... Babington and his conspirators were executed, as was Mary. So, in 1586 one plot suceeded in its goal to execute a monarch.