Cornwallis-West married
Mary Eupatoria ("Patsy") Fitzpatrick, daughter of . Frederick Fitzpatrick and Lady Olivia Taylour (daughter of the
2nd Marquess of Headfort), on 3 October 1872 at
Dublin. Patsy, a prominent mistress of King
Edward VII, was known as a great beauty and leading socialite. They had three children, all of whom endured divorce: •
Mary Theresa ("Daisy") Cornwallis-West (1873–1943), who married Prince
Hans Heinrich XV von Hochberg (going by the name Henry of Pless from 1914). •
George Frederick Myddleton Cornwallis-West (1874–1951), second husband of
Lady Randolph Churchill (the American heiress formerly known as
Jennie Jerome), mother of
Winston Churchill. After their 1914 divorce, he married the actress and beauty
Mrs Patrick Campbell (formerly Beatrice Tanner). •
Constance Edwina ("Shelagh") Cornwallis-West (1875–1970), who married
Hugh Grosvenor, 2nd Duke of Westminster. They divorced and she married her private secretary, Captain John Fitzpatrick Lewis, 14 years her junior. Cornwallis-West died in July 1917, aged 82. His widow died in July 1920, shortly after returning from
Monaco, at her family's Arnewood House which has a half-wooded holding north of her other mansion: Newlands, near
Milford-on-Sea in Hampshire. , Denbighshire ==Newlands Manor==