Al’umar Arma ƙabila ce ta tsakiyar kwarin Kogin Neja, waɗanda suka fito daga maharan Maroko da suka mamaye ƙarni na 16. Sunan, amfani da sauran ƙungiyoyin, sun sami asali daga kalmar ar-mutumin Ruma ( Larabci: الرماة‎ ) "fusiliers". Ƙabilar Arma ta bambanta da (amma wani lokacin ana rikita shi da) mutanen Zarma miliyan 3.6 na yammacin Nijar, waɗanda suka gabaci mamayar Morokko kuma suna magana da harshen Zarma, kuma memba ne na yaren Songhay . Ya zuwa shekarar 1986, akwai wasu mutane Arma da suka nuna kansu a cikin Mali a cikin Mali, galibi a kusa da Timbuktu, tsakiyar Niger lanƙw wasa da Inner Niger Delta . Balaguro ta 1590 da aka aika don cinye hanyoyin cinikayyar Daular Songhai ta daular Saadi ta Maroko ta ƙunshi mutane dubu huɗu na Maroko, 'yan gudun hijirar Morisco da baƙon Turai, masu makamai da kayan tarihi irin na Turai. Bayan halakar daular Songhai a cikin 1591, Marokkowa suka zauna a cikin Djenné, Gao, Timbuktu da manyan biranen kogin Neja. Ba su da ikon yin iko a waje da manyan ganuwar su, a cikin shekaru goma Maroko ta yi watsi da shugabannin balaguron.