In British colonial Nigeria, the military was more heterogeneous than previously thought and British ideas about “martial races” changed depending on local reactions to recruiting. In the early twentieth century British officers saw the northern Hausa and southwestern Yoruba, who dominated the ranks, as civilized “martial races.” The Yoruba stopped enlisting given new prospects and protest, and southeasterners like the Igbo rejected recruiting given language difficulties and resistance. The British then perceived all southern Nigerians as lacking martial qualities. Although Hausa enlistment also declined with opportunities and religious objections, the inter-war army developed a northern ethos through Hausa language and the northern location of military institutions. The rank-and-file became increasingly diverse including northern and Middle Belt minorities, seen by the British as primitive warriors and as insurance against Muslim revolt, enlisting because of poverty. From 1930, military identities in Nigeria polarized with uneducated northern/Middle Belt infantry and literate southern technicians.