E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
St. Barbary, the patron saint of arsenals and powder magazines. Her father delivered her up to Martian, governor of Nicomedia, for being a Christian. After she had been subjected to the most cruel tortures, her unnatural
father was about to strike off her head, when a lightning flash laid him dead at her feet. Hence, those who invoke saints select St. Barbary in thunderstorms. (See BARBE.)
Roan Barbary. The favourite horse of Richard II. (See HORSE.)
O, how it yearned my heart when I beheld
In London streets that coronation day.
When Bolingbroke rode on roan Barbary!
That horse that thou [Rich. II.] so often hast bestrid,