This article studies the socialist “fronde” at the French national Assembly during the 14th parliamentary term (2012-2017). The “fronde” was an episode of high voting indiscipline within the (majority) socialist group on a string of votes pertaining to the core of the government’s economic policy. The article gives a chronological account of the episode, emphasizing the actors’ own narrative (members of parliament and their collaborators). Combining an ethnographic approach with prosopographical data and historical data on roll-call votes at the Assembly since 1993, it confronts the indigenous accounts to a statistical objectivation of the determinants of voting indiscipline, and puts it in historical perspective. By its magnitude, its actors and its practices, the “fronde” is shown to be an exceptional episode, characteristic of the 14th term. However, it is also shown to take place in the context of a long-term waning of party discipline within the socialist parliamentary group, and to reflect progressive changes in the management of internal dissent within the socialist group and party.