[2] Omar Tall's message appealed to a large cross-section of the Sahelian population in the mid 19th century, including Fula, Soninke, Moors, and others.

After a series of emissaries to Tall were rebuffed, and one prominent griot even converted to Islam, Yambi pre-emptively attacked the community but was defeated in September 1852.

His first moves were to the north, with the Jallonke general Modi Mamadu Jam leading the conquests of Makhana and Guidimakha.

In 1860 Omar Tall made a treaty with the French that recognized his, and his followers', sphere of influence in Futa Toro and assigned them the Bambara states of Kaarta and Segu.

[9] In January 1861 the Massina army was mobilized under the leadership of Ba Lobbo with 8,000 cavalry, 5,000 infantry and 1,000 musketeers and was joined at Tio, on the right bank of the Niger opposite Sansanding, by what was left of the Bamana forces.

[11] After a decisive victory in the Battle of Segou on March 10, 1861, Tall made the city the capital of his Toucouleur Empire.

While suppressing the revolt in the spring of 1863, Omar Tall reoccupied the city of Hamdullahi, but in June the rebel forces besieged his army there.

[5]: 109 Ahmadu's brothers Aguibou and Mokhtar, who had been left in Dinguiraye during the wars against Segou and Massina, attempted to take power themselves in Nioro and Koniakary during the 1870s, but were both defeated and imprisoned.

[15] Omar Tall's conquest of the Bamana Empire was facilitated by internal instability and decentralization, but this made rule of the middle Niger difficult.

In the 1860s inflation was rampant, and troops raided widely to obtain supplies, since the state did not have a firm enough grip on the country to tax the people and pay or feed soldiers.

[8]: 417 At least by the reign of Ahmadu, the government of the Empire was highly structured, with governors of the various provinces seconded by cadis, military commanders and tax collectors, all appointed by the Khalifa.

Ministers based in Segou managed various portfolios such as justice, the Niger river fleet, the public treasury, relations with Europeans and other foreign powers, commerce, etc.

[16] A large swath of the Sahel territory that once encompassed the Toucouleur Empire is now today Muslim due to the campaigns of Omar Tall.