Thirteen principal conspirators are commonly listed as members of the 1605 Gunpowder Plot.
Robert Catesby organized the conspiracy, which aimed to kill King James I and destroy the House of Lords. The plot developed from a smaller group into a wider network of Catholic conspirators, including Thomas Wintour, Thomas Percy, John Wright, Christopher Wright, Robert Keyes, Thomas Bates, Robert Wintour, John Grant, Ambrose Rookwood, Sir Everard Digby, Francis Tresham, and Guy Fawkes.
The number can cause confusion because only eight conspirators were executed in January 1606. Others died during the armed confrontation at Holbeche House or escaped prosecution through death or other circumstances.
Historians therefore distinguish between the commonly counted principal plotters and the smaller number who were tried and executed.