E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A conspiracy to assassinate Charles II. and his brother James on their way from Newmarket. As the house in which the king was lodging accidentally caught fire, the royal party left eight days sooner than they had intended, and the plot miscarried. It was called the Rye House Plot because the conspirators met at the Rye House Farm, in Hertfordshire. (1683.)