Adamawa Wars in the context of Schutztruppe

The Sokoto Caliphate (Arabic: دولة الخلافة في بلاد السودان, literally: Caliphate in the Lands of Sudan), also known as the Sultanate of Sokoto, was a Sunni Muslim caliphate in West Africa. It was founded by Usman dan Fodio in 1804 during the Fulani jihads after defeating the Hausa Kingdoms in the Fulani War. The boundaries of the caliphate extended to parts of present-day Cameroon, Burkina Faso, Niger, and Nigeria. By 1837, the Caliphate had a population of 10-20 million people, becoming the most populous empire in West Africa. It was dissolved when the British, French, and Germans conquered the area in 1903 and annexed it into the newly established Northern Nigeria Protectorate, Senegambia and Niger and Kamerun (the latter during the Adamawa Wars) respectively.

The caliphate emerged after the Hausa King Yunfa attempted to assassinate Usman Dan Fodio in 1802. To escape persecution, Usman and his followers migrated towards Gudu in February 1804. Usman's followers pledged allegiance to Usman as the Commander of the Faithful (Amīr al-Muʾminīn). By 1808, the Sokoto Caliphate had gained control over Hausaland and several surrounding states. Under the sixth caliph Ahmadu Rufai, the state reached its maximum extent, covering a large swath of West Africa. In 1903, the twelfth and last caliph Attahiru was assassinated by British forces, marking the end of the caliphate.

The 1900s (pronounced "nineteen-hundreds") was the decade that began on January 1, 1900, and ended on December 31, 1909. The Edwardian era (1901–1910) covers a similar span of time. The term "nineteen-hundreds" is sometimes also used to mean the entire century from January 1, 1900, to December 31, 1999 (the years beginning with "19").

The Scramble for Africa continued, with the Orange Free State, South African Republic, Ashanti Empire, Aro Confederacy, Sokoto Caliphate and Kano Emirate being conquered by the British Empire, alongside the French Empire conquering Borno, the German Empire conquering the Adamawa Emirate, and the Portuguese Empire conquering the Ovambo. Atrocities in the Congo Free State were committed by private companies and the Force Publique, with a resultant population decline of 1 to 15 million. From 1904 to 1908, German colonial forces in South West Africa led a campaign of ethnic extermination and collective punishment, killing 24,000 to 100,000 Hereros and 10,000 Nama. The First Moroccan and Bosnian crises led to worsened tensions in Europe that would ultimately lead to World War I in the next decade. Cuba, Bulgaria, and Norway became independent.