Lady Frances Coningsby (1707?-1781) was the daughter of Thomas, 1st Earl Coningsby, and Lady Frances Jones. In July 1732 she married Charles Hanbury Williams. They had two daughters: Frances married William Capel, 4th Earl of Essex, and Charlotte married Robert Boyle Walsingham, youngest son of the Earl of Shannon. Williams was notorious for his infidelities, and infected his wife with syphilis; on receiving the diagnosis in 1742, she refused to see him again and obtained a legal separation and custody of their daughters. In 1762, following his death, an Act of Parliament authorised her to revert to using her maiden name. In 1773 she was put under the care of Dr William Battie, physician of St Luke’s Hospital for Lunaticks, and was a recluse for the rest of her life. It is unclear whether her condition was caused by syphilis, by the mercury she was administered in an attempt to cure it, or some other cause. [See Mary Margaret Stewart “Moving upon Glass”: The Madness of Lady Frances Coningsby, in Women, Gender, and Print Culture in Eighteenth-Century Britain, ed. Temma Berg & Sonia Kane (Bethlehem, Leigh University Press, 2013, pp. 167-196]