In early 1881, tribal friction along the ill-defined border between French-controlled Algeria and the Regency of Tunis escalated into a major geopolitical crisis. The Kroumir tribe, semi-autonomous pastoralists living in the rugged northwestern mountains of Tunisia, engaged in routine cross-border cattle raids against Algerian tribesmen. Similar skirmishes had occurred for decades without triggering imperial invasion.
However, miscommunication between French military intelligence and Paris, coupled with exaggerated reports from colonial officials, framed these local border clashes as an organized, hostile invasion of French territory backed by the Bey of Tunis. French Prime Minister Jules Ferry seized upon these inflated border reports to justify military intervention without declaring war. In April 1881, over 30,000 French troops crossed into Tunisia, crushing Kroumir resistance and marching on Tunis.
Bey Muhammad III as-Sadiq was forced to sign the Treaty of Bardo on May 12, 1881, surrendering defense and foreign affairs to France. What began as a localized livestock feud ended with the creation of the French protectorate over Tunisia.