Portrait by Pietro Annigoni

Deborah Vivien Freeman-Mitford (born March 31, 1920), Dowager Duchess of Devonshire, is the last of the noted Mitford sisters.

She married Andrew Cavendish, 11th Duke of Devonshire in 1941. At the time he was not expected to inherit the dukedom but his older brother William was killed in combat in 1944. Andrew became duke, and Deborah became duchess, when the 10th Duke died in 1950.

In 1999 she was appointed a Dame Commander of the Royal Victorian Order (DCVO) by Queen Elizabeth II. She has three children, including the 12th Duke. She is a grandmother of fashion model Stella Tennant .

Deborah became the Dowager Duchess of Devonshire in 2004 when her son inherited the Dukedom upon the death of her husband of over 60 years.

Deborah Devonshire is the author of several books about Chatsworth House:

• Chatsworth: The House (1980; revised edition 2002)
• The Estate: A View from Chatsworth (1990)
• The Farmyard at Chatsworth (1991) - for children
• Treasures of Chatsworth: A Private View (1991)
• The Garden at Chatsworth (1999)
• The Chatsworth Cookery Book (2003)

She has also contributed to The Spectator and published a collection of essays, Counting My Chickens and Other Home Thoughts