The Adamawa Wars (1899–1907) were initially a series of military expeditions and border conflicts between the German Schutztruppe in Kamerun and the Fula and Hausa Sunni Muslim states and tribes that were a part of the Sokoto Empire (a Caliphate formed during the Fulani Jihad), particularly the Emirate of Adamawa in the northern half of the region. After these territories were annexed major resistance continued for years and several uprisings occurred.

The territories to the north of the portion of Kamerun under direct German control were part of either the Bornu or Sokoto Empires, the latter was (along with the Ottoman Empire) one of the worlds last remaining Caliphates. While the power of Bornu to resist was weakened after its temporary conquest by the Sudanese warlord Rabih az-Zubayr, Sokoto remained intact. Sokoto was an Islamic empire that controlled semi-autonomous emirates, the largest being Adamawa. By 1890 Adamawa was weakened by internal struggle, as a Mahdist state had developed within the Emirate, and its borders overlapped with German colonial claims in the region, though it remained defiant on ceding territory.

For economic and political reasons, the Germans were determined to expand the colony into Adamawa, so exploration expeditions to survey the region began, with the intention of eventually taking it by force. However, until 1898, the Germans were still primarily focused on the Bafut Wars, attempting to conquer and pacify the chiefdoms of central and northwestern Kamerun, rather than spreading northeast.

The military expeditions to expand German Kamerun north toward the Sahel, under the pretext of ending the Islamic slave trade in the region, began in earnest in January 1899, with the Schutztruppe under the command of Captain Oltwig von Kamptz leaving Douala for the north to subjugate the Tibati Sultanate in southern Adamawa. Tibati resisted fiercely, and the Bulu tribe on the former southern border of Adamawa rose up in revolt, the Bulu warriors marching to Kribi on the coast and destroyed the Catholic mission there. Only after an increase in troops in the colony and a severe campaign lasting until 1901 was the region pacified and the Tibati Sultan captured, his palace taken by storm.

The Germans had in the late 1890s taken a more military approach with Adamawa with the conquest of the Tibati Sultanate, which was favored by the governor of the Kamerun colony Jesko von Puttkamer, despite attempts to peacefully penetrate the region through Christian missionaries, the approach favored by Adolph Woermann, an influential merchant in the colony. However, in the summer of 1901, and despite previous conflict with the Emirate, Lieutenant Hans Dominik was ordered to meet with Emir Zubeiru bi Adama to reach an agreement on the contested territories and for the prospect of turning Adamawa into a protectorate of the German Empire, as Germany claimed all of the territory between the Sanaga River and Lake Chad, and conduct an expedition to the far north. However, ignoring orders from governor Puttkamer, Colonel Rudolf Cramer von Clausbruch [de] brought his Schutztruppe from the west and invaded Adamawa, storming the city of Ngaoundéré on August 20. Seeing an opportunity to claim their portion of the Emirate, the British sent a force under Colonel Thomas Morland from Nigeria to attack and occupy Yola in September, causing Emir Zubairu to flee from his own capital city.

Dominik with his force fought their way northwest to Ngaoundéré where they linked up with Clausbruch's troops before attacking across the Benue River capturing the city of Garoua. One of Fula rulers opposing the German advance (like most of his contemporaries) was Mal Hammadou, whose forces were devastated by the Germans. Lieutenant Radke, leading a force of 47 men, marched on Hammadou's capital of Rei Buba by November, and attacked a strong Fulani force at a position just outside of the town, almost losing the battle, but being able to defeat and route the enemy in a final bayonet charge before marching on Rei Buba itself. Hammadou's capital was bombarded by cannons before being captured, causing him to flee. The Germans replaced him as local leader (holding the title Ardo) with Bouba Djama.

Zubairu went to gather support in Sokoto and returned with a large force of Fulani cavalry and infantry, and also appealed for support from the Mahdist movement in Adamawa, no longer an enemy to the Emir since the death of Hayatu ibn Sa'id in the 1890s, and who sympathized with the Emir's call for jihad against the German invaders. However, informants told the Germans of Zubairu's plans, despite this the Germans wanted to hold peace talks in Garoua and use Zubairu as a puppet, allowing him to stay in power in return for his help winning over the other sultanates and emirates in Sokoto. Instead the Emir attacked Garoua with a much larger force in November 1901. However Zubairu was defeated and routed, his force suffered some 300 dead. Fleeing toward Maroua, Zubairu tried to raise another force, but Lieutenant Dominik led a small force of Schutztruppe in pursuit. At the decisive Battle of Maroua [de] another Fulani force of cavalry led by Zubairu and Ahmadu Rufai, supported by Mahdist sympathizers, was again defeated by the Schutztruppe, although Zubairu and Rufai again escaped.

After the Battle at Maroua, Zubairu and many of his supporters fled into the Mandara Mountains deeper into the Sokoto Empire. Hans Dominik had the local Fulani ruler Bakari Yadji executed for assisting Zubairu's escape in this region to Madagali, and his son Hamman was placed as local ruler instead. With the military defeat and expulsion of Zubairu as a spiritual and political overlord of the Fulani in Adamawa, the German colonial administration annexed the region from Sokoto, broke the historic ties to the Fulani's center Yola and replaced them with the connection to the seat of the residency Garoua as a new political and economic center.