The Kaabu Empire (1537–1867), also written Gabu, Ngabou, and N’Gabu', was a Mandinka kingdom of Senegambia centered within modern northeastern Guinea-Bissau but extending into Casamance in Senegal. It rose to prominence in the region thanks to its origins as a former province of the Mali Empire. After the decline of the Mali Empire, Kaabu became an independent kingdom. It was eventually annexed by Futa Jallon during the 19th century Fula jihads prior to the incorporation of the area into the Portuguese and French spheres of influence during the Scramble for Africa.
The Mandinka arrived in Guinea-Bissau around the year 1200. One of the generals of Sundiata Keita, Tirmakhan Traore, conquered the area making Kaabu one of Mali's western tinkuru, or provinces in the 1230s. By the beginning of the 14th century, much of Guinea-Bissau was under the control of the Mali Empire and ruled by a Farim Kaabu (Commander of Kaabu) loyal to the Mansa of Mali. As in many places that saw Mandinka migrations, much of Guinea-Bissau's native population was dominated or assimilated. Resisters being sold into slavery via the trans-Sahara trade routes to Arab buyers. Although the rulers of Kaabu were Mandinka, many of their subjects were from ethnic groups who had resided in the region before the Mandinka invasion.
After the middle of the 14th century, Mali saw a steep decline due to raids by the Mossi to their south and the growth of the new Songhai Empire. During the 16th century, Mali lost many of its provinces reducing it to not much more than the Mandinka heartland. Succession disputes between heirs to Mali's throne also weakened its ability to hold even its historically secure possessions in Senegal, the Gambia, and Guinea-Bissau. Free of imperial oversight, these lands splintered off to form independent kingdoms. The most successful and longest lasting of these was Kaabu, which became independent in 1537. Kaabu's governor, Sami Koli, became the first ruler of an independent Kaabu. He was the grandson of Tiramakhan Traore.
Kaabu carried on the legacy of the Mali Empire much in the same way the Byzantine Empire preserved the culture and social structure of the Roman Empire. The rulers of the Kaabu Kingdom believed their right to rule came from their history as an imperial province. The kings of independent Kaabu discarded the title of Farim Kaabu for Kaabu Mansaba. At the Kaabu capital of Kansala, the Kaabu Mansaba controlled the increasingly valuable slave trade with Europeans. They specifically traded with the Portuguese, supplying many slaves to the Cape Verde Islands and the Americas. Among the provinces of the Kabu empire were Firdu, Pata, Kamako, Jimara, Patim Kibo, Patim Kanjaye, Kantora, Pakane Mambura, Kudura, Nampaio and Pacana.
Kaabu, despite its ties to Mali, appears to have run in a quite different matter. Mali was established as a federation of chiefs, and the government operated with an assembly of nobles to which the Mansa was largely responsible. Kaabu, however, was established as a military outpost. So it is of little surprise that the kingdom's government was militaristic. The ruling class was composed of warrior-elites made rich by slaves captured in war. These nobles were known as Nyancho (Ñaanco) or the Manneh and the Sanneh and held much of the power in the state. These nobles were instrumental in the decline of Kaabu due to internal feuds between powerful Nyancho with their respective slave armies.
Mandinka oral tradition holds that Kaabu was the actual birthplace of the Mande musical instrument, known as the Kora. A kora is built from a large calabash cut in half and covered with cow skin to make a resonator, and has a notched bridge like a lute or guitar. The sound of a Kora resembles that of a harp, yet with its gourd resonator it has been classified by ethnomusicologists such as Roderick Knight as a harp-lute. The Kora was traditionally used by the griots as a tool for preserving history, ancient tradition, to memorize the genealogies of patron families and sing their praises, to act as conflict intermediaries between families, and to entertain. Its origins can be traced to the time of the Mali empire and linked with Jali Mady Fouling Diabate, son of Bamba Diabate. According to the griots, Mady visited a local lake in which he was informed that a genie who granted wishes had resided. Upon meeting him, Mady requested that the genie make him a brand new instrument that no griot had ever owned. The genie accepted, but only under the condition that Mady release his sister into his custody. After being informed, the sister agreed to the sacrifice, the genie complied, and hence, the birth of the legendary Kora. Aside from oral testimony, historians propose that the Kora appeared with the apogee of war chiefs from Kaabu, allowing the tradition to spread throughout the Mande area until it was made popular by Koryang Moussa Diabate in the 19th century.
According to Mandinka tradition, Kabu had been in existence and remained unconquered for eight hundred and seven years. There were 47 Mansas in successions. The power of Kaabu began to wane during the eighteenth and nineteenth centuries as militant Islamic leaders among the Fula people, with help from some Soninke and Mandinka chiefs, rallied against non-Muslim states in the region. This culminated in 1865 in a regional jihad led by the Imamate of Futa Jallon known as the Turban Kelo or Kansala War. Before then Kaabu had successfully repulsed on numerous occasions various armies at the fort of Berekolong. It was due to Kaabu's decline and its internal infighting that in 1867 Kaabu came under siege from an army led by Alfa Molo Balde, a general from the Imamate of Futa Jallon. After the eleven-day Battle of Kansala, Mansaba Janke Waali sanneh (also called Mansaba Dianke Walli) ordered the city's gunpowder stores to be set afire. The resulting explosion killed the Mandinka defenders and many of the attackers. Without Kansala, Mandinka hegemony in the region came to an end. The remains of the kingdom were under Fula control until the Portuguese suppression of the kingdom around the turn of the 20th century.