Cramped on the fragmented grounds of Billancourt, Louis Renault gradually bought Seguin Island in 1919. After extensive work to raise and stabilize the soil, a new plant was built and put into service from 1929. It is the flagship of the company. It then hosts a strong diversity of production: automotive, trucks, railcars, locotractors... Under German control during the war, the Billancourt site was bombed three times in 1942 and 1943. Rebuilt at the liberation, then nationalized after the death of Louis Renault, then accused of collaboration, the factory of the island Seguin produces the 4CV, emblematic model of the post-war period, then for 30 years the famous Renault 4. But after the thirty glorious, Billancourt has become the symbol of social protest and suffers from its structural handicaps: enclavement making supply difficult and construction on 5 floors on the island, greatly complicating the industrial scheme. Despite a modernization in 1983, the site did not withstand the financial difficulties of Renault in the 1980s and the decision to close the site was announced in 1989 and effective at the beginning of 1992.