E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Preston and his Mastiffs.
To oppose Preston and his mastiffs is to be foolhardy, to resist what is irresistible. Christopher Preston established the Bear Garden at Hockley-in-the-Hole in the time of Charles II. The Bible says he that employs the sword shall perish by the sword, and Preston was killed in 1709 by one of his own bears.