The Arma people is anethnic group of the middle Niger River valley, descended from Moroccan invaders of the 16th century. The name, applied by other groups, derives from the word ar-rumah (Arabic: الرماة) 'fusiliers'.
The Arma ethnicity is distinct from (but sometimes confused with) the 3.6 million Zarma people of western Niger, who predate the Moroccan invasion and speak the Zarma language, also a member of the Songhay languages.
The Moroccan invasion of the Songhai Empire began with an expedition sent in 1590 by Sultan Ahmad al-Mansur of the Saadian dynasty, which ruled over Morocco at the time. The Saadian army, led by Judar Pasha, arrived in the Niger valley region (in present-day Mali) in 1591 and won its first and most decisive victory against the forces of Askia Ishaq II at the Battle of Tondibi and occupied the capital of Gao shortly after.
After this victory, however, the Moroccans struggled to have their authority accepted in the region and continued to wage a protracted war with the remnants of the defeated Songhai Empire. The Saadians did achieve their aim of controlling the Trans-Saharan trade routes, which secured a supply of gold and slaves. In the long term the Pashalik of Timbuktu, a small state centered on Timbuktu and controlled by the Arma people, continued to rule a territory stretching roughly from Gao to Djenné and nominally recognized the authority of the Saadian dynasty and the later Alaouite dynasty in Morocco as late as the 19th century. Trans-Saharan trade, however, ultimately declined as a result of the political fragmentation of the region and of the increasing European presence in West Africa.
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