The ancient history of what is now Guinea-Bissau is poorly understood by historians. The earliest inhabitants were the Jola, Papel, Manjak, Balanta, and Biafada peoples. Later the Mandinka and Fulani migrated into the region in the 13th and 15th centuries respectively. They pushed the earlier inhabitants towards the coast and onto the Bijagos islands.
The Balanta and Jola had weak or non-existent institutions of kingship but emphasised decentralization, with power invested in heads of villages and families. The Mandinka, Fula, Papel, Manjak, and Biafada chiefs were vassals to kings. The customs, rites, and ceremonies varied, but nobles commanded all the major positions, including the judicial system. Social stratification was seen in the clothing and accessories of the people, in housing materials, and in transportation options. Trade was widespread between ethnic groups. Items traded included pepper and kola nuts from the southern forests; iron and iron utensils from the savannah-forest zone; salt and dried fish from the coast; and Mandinka cotton cloth.
According to oral tradition, the Kingdom of Bissau was founded by the son of the king of Quinara (Guinala), who moved to the area with his pregnant sister, six wives, and subjects of his father's kingdom. Relations between the kingdom and the Portuguese colonisers were initially warm, but deteriorated over time. The kingdom strongly defended its sovereignty against the Portuguese 'Pacification Campaigns', defeating them in 1891, 1894, and 1904. However, in 1915 the Portuguese under the command of Officer Teixeira Pinto and warlord Abdul Injai fully absorbed the kingdom.
The Biafada people inhabited the area around the Rio Grande de Buba in three kingdoms: Biguba, Guinala, and Bissege. The former two were important ports with significant lançado communities. They were subjects of the Mandinka mansa of Kaabu.
In the Bijagos Islands, people of different ethnic origins tended to settle in separate settlements. Great cultural diversity developed in the archipelago.
Bijago society was warlike. Men were dedicated to boatbuilding and raiding the mainland, attacking the coastal peoples as well as other islands. They believed that at sea they had no king. Women cultivated the land, constructed houses, and gathered and prepared foods. They could choose their husbands, and warriors with the best reputations ranked at the top of respected status. Successful warriors could have many wives and boats, and were entitled to one third of the spoils gained by warriors who used their boats in any expedition.
Bijago night raids on coastal settlements had significant effects on the societies attacked. Portuguese traders on the mainland tried to stop the raids, as they hurt the local economy. But the islanders also sold considerable numbers of villagers captured in raids as slaves to the Europeans. With colonisation underway in other parts of Africa and the Americas, demand for workers was high and the Europeans sometimes pushed for more captives to be taken.
The Bijagos were mostly safe from enslavement, as they were out of reach of mainland slave raiders. Europeans avoided having them as slaves. Portuguese sources say the children made good slaves but not the adults, who were likely to commit suicide, lead rebellions aboard slave ships, or escape once reaching the New World.
Kaabu was established first as a province of Mali through the conquest in the 13th century of the Senegambia by Tiramakhan Traore, a general under Sundiata Keita. By the 14th century much of Guinea Bissau was under the administration of Mali. It was ruled by a farim kaabu (commander of Kaabu).
Mali declined gradually, beginning in the 14th century. By the early 16th century, the expanding power of Koli Tenguella cut off formerly secure Mali.
Kaabu became an independent federation of kingdoms. The ruling classes were composed of elite warriors known as the Nyancho (Ñaanco) who traced their patrilineal lineage to Tiramakhan Traore. The Nyancho were a warrior culture, reputed to be excellent cavalry men and raiders. The Kaabu Mansaba was seated in Kansala, in what is today the Gabú region.
The slave trade dominated the economy, and the warrior classes grew rich with imported cloth, beads, metalware, and firearms. Trade networks with Arabs and others to North Africa were dominant up to the 14th century. In the 15th century, coastal trade with the Europeans began to increase. In the 17th and 18th centuries an estimated 700 slaves were exported annually from the region, many of them from Kaabu.
In the late 18th century, the rise of the Imamate of Futa Jallon to the east posed a powerful challenge to the animist Kaabu. During the first half of the 19th century, civil war erupted as local Fula people sought independence. This long-running conflict was marked by the 1867 Battle of Kansala; the Fuladu effectively defeated the Kaabu and dominated the area thereafter. But some smaller Mandinka kingdoms survived until their absorption into Portuguese colonies.
