Louis Emanuel Jean Guy de Savoie-Carignan de Soissons CVO RA FRIBA (1890–1962) was the younger son of Charles, the Count de Soissons. An architect, he was called for professional purposes Louis de Soissons.
de Soissons was born in Montreal, Canada, but moved in childhood with his family to London. In 1913 he won the first year of the Henry Jarvis scholarship of the Royal Institute of British Architects, enabling three years of European travel and study.
The first major commission of the practice he set up (Louis de Soissons Partnership) was the 'master plan' (so-called - a very early use of the term) for Welwyn Garden City (1920), a planned town created by Ebenezer Howard, on cheap redundant farmland. Louis de Soissons was appointed architect for the town in 1920 and the practice was significantly involved in its development over the next 60 years. He designed the concrete Shredded Wheat factory for the eponymous Canadian company.
Other important early projects included the Home Office and Duchy of Cornwall Estates in London, where the future Edward VIII was the effective client and the Nag's Head Estate in Bethnal Green, London, E2 which was one of the few private "slum clearance" projects undertaken by a private landlord. When young he had been much influenced by 18th century Italian architecture, and gained a reputation as a classical architect, but with a deep humanism resulting from his new town work.
After the Second World War the firm expanded to Plymouth and Exeter to carry out a wide variety of architectural work. Nearly 50 War Cemeteries were designed for the Commonwealth War Graves Commission in Greece and Italy. Later the practice’s buildings included a number of important buildings, such as the Wellcome Foundation, The Leathersellers Company, (a reconstruction in 1948 after wartime bombing), the Royal College of Obstetricians and Gynaecologists in Regent's Park and the International Wool Secretariat in Carlton Terrace, London. He also designed the Hobbs' Gates at The Oval cricket ground, in memory of Sir Jack Hobbs, the noted Surrey and England player, and a statue of George VI.