Jos, a central Nigerian city engulfed by deadly violence in September 2001, offers a unique case study for exploring what happens when a modern metropolis lacks the institutional capacity to regulate its competing groups, and latent rivalries ignite into widespread, systematic brutality. Emerging from combined political and cultural dynamics radically different from those of better-known examples, such as Jerusalem and Belfast, Jos provides fresh insights into the roles of group concentration and conflict framing in engendering territoriality and violence in the city. As this paper shows, Jos' colonial history in tin mining, waves of migration, and an urban policy of sociospatial differentiation have shaped and intersected with the contemporary politics of ethnicity to foster explosive relations between Christians and Muslims. Building on literature and primary data from interviews and discussions with surviving residents, the paper explicates how group geography and conflict became so entangled, leading to the so-called 'Jos crisis'. Some of the boys were my neighbours. They set the house on fire but I remained hidden inside and watched as they used big sticks and machetes on four people. Three of the people they killed were my family.1 This is just one among many stories of neighbours preying on neighbours during the violent conflict that engulfed a central Nigerian city in September 2001. A decade later, when this resident of Jos was telling me how his three siblings were murdered and his home set ablaze by people he knew well, burn scars from the incident were still visible on his face and arms. Overnight, it seemed, neighbourhoods that were once scenes of convivial coexistence became fierce battlegrounds of ethnic cleansing between Christians and Muslims. The crux of the conflict is the dispute over indigeneity. On one side are three ethnolinguistic groups indigenous to Jos -Afizere, Anaguta and Berom -who are consequently considered indigenes; on the other are the Hausa, who are more recent arrivals to the Jos Plateau than the indigenes but who established themselves in urban Jos before other groups.2 Although the conflict is about indigeneity and ownership of the