France, 1940. German troops have just invaded the country, but in the rural idyll of the family chateau inhabited by 20-year-old Mellie with her impoverished aristocrat father Alexandre and adolescent cousin Robinson, the war still seems far away, apart from the fact that Mellie's rich and unpopular fiancé André has been drafted into the army. For Robinson and his friends the same age, including the temperamental Bertrand, the war is merely a game they play in the remoteness of the blue island in the lake.

Une famille formidable is a French romantic comedy television series broadcast since September 17, 1992. It details the goings on of a family, and follows them as they grow up. As of 2008, the cast is the same as the 1992 cast, an unusual feat for a program with a run of this length. In 2012, during the broadcast of the season 9 is celebrated twenty years of the series.