Mary Adelaide Virginia Thomasina Eupatoria ("Patsy") Cornwallis-West (née FitzPatrick; 28 October 1854[1] – 21 July 1920) was an Anglo-Irish aristocrat and a prominent mistress of the future King Edward VII.

Cornwallis-West was born into an upper-class Irish family as the daughter of the Rev.

[2] The affair was discovered, and in 1872 she was married to the Lord-Lieutenant of Denbighshire William Cornwallis-West.

They lived at Ruthin Castle and had three children: Cornwallis-West became notorious for using her influence over the Prince of Wales to arrange marriages for her children, particularly the marriage of her younger daughter to the wealthy Duke of Westminster.

[3] In 1915, she began a relationship with a much younger shell-shocked soldier, Patrick Barrett, nursed in the Duchess of Westminster's hospital in Le Touquet.