Journal article: Each year, around 100,000 people acquire French nationality, most often based on their family situation (marriage, birth and childhood in France, being parents of French children, etc.). These acquisitions of nationality are also linked to historical and geopolitical transformations. Since the early 1960s, more than 200,000 individuals who lost their French nationality, in many cases when colonized territories became independent, have been reintegrated. The history of reintegration, a discreet and little-known procedure, sheds light on some of the ‘nationality trouble’ of the post-colonial era.