Desmond Walter Guinness (8 September 1931 – 20 August 2020) was anAnglo-Irish author ofGeorgian art and architecture, a conservationist and the co-founder of theIrish Georgian Society. He was the second son of the author and brewerBryan Guinness, 2nd Baron Moyne, and his then wifeDiana Mitford (later Lady Mosley).

In 1958, he bought Leixlip Castle,Leixlip,County Kildare, Ireland, where he lived with both his first wife,Princess Henriette Marie-Gabrielle von Urach, generally known as Mariga, and later his second wife, the former Penelope Cuthbertson, whom he married in 1984.^[1]

Born on 8 September 1931, Guinness was the second son of the authorBryan Guinness andDiana Mitford; his elder brother wasJonathan. Bryan succeeded as the 2ndBaron Moyne in November 1944. Desmond's mother divorced the then Bryan Guinness after five years and married the head of the British fascist Blackshirt movement,Oswald Mosley, inBerlin in 1936. Due to Mitford's interest in fascism, her father-in-law the1st Baron had arranged for surveillance from 1935 onward, including by one of Guinness's governesses, andMI5 even noted a plan for her to visitHitler with her sons. Mitford was interned in 1940, and Guinness later recalled visiting her inHolloway Prison when he was 10.^[2]

He was educated atEton andGordonstoun, and studied French and Italian atChrist Church, Oxford. After completingNational Service, he moved to the estate of Lord Moyne, his father, near thePhoenix Park inDublin, as Lord Moyne lived for six months a year inIreland, and his mother had also moved to Ireland with Mosley, first living inClonfert, then inFermoy.^[2]

Guinness was married atOxford in 1954 toPrincess Henriette Marie-Gabrielle von Urach, daughter ofFürstAlbrecht von Urach and a granddaughter ofKing Mindaugas II of Lithuania, who was generally known as "Mariga". Guinness bought Leixlip Castle and its residual 180-acre farm for £15,500, one third of his assets, in 1958, and he and his wife settled there.^[2]

Mariga Guinness moved to London alone in 1969, later lived inCounty Antrim, and later still returned to Leixlip Castle. The Guinnesses divorced in 1980, and Mariga died some years later.^[3]

Desmond and Mariga founded theIrish Georgian Society in April 1958 to help to preserve Irish architecture of all periods. This was timely as the Irish planning laws were enacted only from 1963.^[4]

The IGS became involved in numerous projects and started publishing quarterly bulletins. Some early preservations or campaigns were at:Damer House (County Tipperary),The Conolly Folly (County Kildare),Mountjoy Square,Tailors' Hall andHume Street (Dublin) and the Dromana Gateway inCounty Waterford.

The IGS also held Georgiancricket matches played to therules of 1744.

Between 1967 and 1979 the Guinnesses bought and started to preserveCastletown House, inCelbridge,Kildare, said to be the finest Palladian house in Ireland.^[5][6]

He was a member of Irish groups such as theIveagh Trust, the CKAS,^[7] the RIAC^[8] and theKildare Street & University Club.

In 1984, Guinness married Penelope Cuthbertson, daughter of the socialiteTeresa Jungman, and a granddaughter of the artistNico Wilhelm Jungmann.^[9]

In more recent years, Guinness founded a scholarship for students of architecture.^[10][11]

He wasMaster of the North Kildare Harriers. He stood down as President of the IGS in 1990.

Guinness died on 20 August 2020, at the age of 88.^[12]

The Guinnesses had a son,Patrick Desmond Carl-Alexander, and a daughter, Marina.^[13] Through Patrick he was a grandfather of the fashion modelJasmine Guinness.^[14] His daughter Marina is a patron of the arts and of Irish musicians includingGlen Hansard,Damien Rice, and the bandKíla. Marina has three children of her own: Patrick (byStewart Copeland ofThe Police), Violet (by photographerPerry Ogden), and Finbar (by record producerDenny Cordell).^[15]

There are no children from his second marriage.^[9][16]

His brother isJonathan Guinness, 3rd Baron Moyne. He was the older half-brother (on his mother's side) ofMax Mosley, former President of theFIA.

His conservation work has been recognised by many American and English cultural groups, andEuropa Nostra. In 1980 he was made an honorary Doctor of Laws atTrinity College Dublin. In 2001 he was made an honorary member of theRoyal Institute of the Architects of Ireland and was awarded the gold medal of theEire Society of Boston.^[17] He was a member of theSociety of Dilettanti in London. In 2006 he was presented with a Europa Nostra award by theQueen of Spain. In 2010 he headed theSaint Patrick's Day parade inSeattle.^[18] In June 2014 he was awarded honorary lifetime membership of theRoyal Dublin Society.^[19]

Guinness wrote the following books:

• Portrait of Dublin (New York: Viking Press, 1967)
• Georgian Dublin (Batsford, B.T., Ltd. 1979)ISBN 978-0-7134-1908-5

three further books with Julius Trousdale Sadler:

• Mr Jefferson, architect (New York: Viking, 1973)ISBN 978-0-670-49261-9
• Palladio: A Western Progress (New York: 1976)ISBN 978-0-670-53732-7
• Newport preserv'd : architecture of the 18th century (New York: Viking Press, 1982)ISBN 978-0-670-50938-6

two with William Ryan:

• Irish Houses and Castles; with William Ryan. (London: Thames & Hudson, 1973).
• The White House: An Architectural History (New York: McGraw-Hill, 1980).ISBN 978-0-07-054352-2

and two with Jacqueline O'Brien, wife of the famous racehorse trainerVincent O'Brien:

• Dublin – A Grand Tour (Weidenfeld & Nicolson, 1994)
• Great Irish Houses and Castles (Harry N. Abrams, Inc.)ISBN 978-0-8109-3365-1 (December 1998) and in paperback (Weidenfeld & Nicolson, September 1993)ISBN 978-0-297-83236-2.

Guinness wrote numerous articles, includingThomas Jefferson: Visionary Architect. Horizon, 22 (1979): 51–55.

• Address on the award to Desmond Guinness of the European Union Prize for Dedicated Service to Heritage Conservation Irish govt. 2007.