Guinea-Bissau sits on the West African coast between Senegal and Guinea, covering 36,125 square kilometers. The mainland extends inland from a coastline marked by estuaries where the Geba, Corubal, and Cacheu rivers meet the Atlantic. The Bissagos Archipelago lies offshore, comprising 88 islands of which approximately 20 hold permanent populations. The terrain grades from coastal mangroves and tidal flats through flat plains to low hills in the interior. No point in the country exceeds 300 meters elevation. The climate divides between a rainy season from June through October and a dry season from November through May. Annual rainfall ranges from 1,400 millimeters in the north to over 2,000 millimeters in coastal zones.
Portuguese navigator Nuno Tristão reached the coast in 1446 during the expansion of Portuguese maritime exploration. The territory became a center of the Atlantic slave trade from the late sixteenth century through the nineteenth century, with Cacheu and Bissau serving as principal export points. The Portuguese established Fortaleza de Cacheu in 1588, constructing a stone fortification that remains standing. Bolama served as colonial capital from 1879 until 1941, when administrative functions transferred to Bissau. Portuguese Guinea existed as a distinct colonial entity from 1879, though Portugal's effective control remained limited to coastal settlements and select interior trading posts until the early twentieth century.
Amílcar Cabral founded the African Party for the Independence of Guinea and Cape Verde, known by its Portuguese acronym PAIGC, in 1956. Cabral was born in 1924 in Bafatá to Cape Verdean parents and trained as an agronomist in Lisbon. The PAIGC initiated armed resistance against Portuguese colonial rule on January 23, 1963. By 1973 the movement controlled approximately two-thirds of Guinea-Bissau's territory and had established administrative structures including schools and medical posts in liberated zones. Assassins killed Cabral in Conakry, Guinea on January 20, 1973. The PAIGC unilaterally declared independence on September 24, 1973 in Madina do Boé, a southeastern town controlled by the movement. Portugal recognized independence on September 10, 1974, following the Carnation Revolution that overthrew the Estado Novo regime in Lisbon.
Luís Cabral, brother of Amílcar Cabral, became the first president upon independence. João Bernardo Vieira, known as Nino Vieira, overthrew Luís Cabral in a 1980 coup and governed until 1999 with an interruption from 1998 to 1999 during a civil war. That conflict began in June 1998 when military forces loyal to General Ansumane Mané rose against Vieira's government, receiving support from Senegal and Guinea in what became a multi-sided intervention. Fighting displaced approximately 350,000 people and ended with Vieira's departure in May 1999. Kumba Ialá won elections in 2000 but the military removed him in 2003. Vieira returned to the presidency through elections in 2005. On March 1, 2009, assassins killed General Batista Tagme Na Waie, chief of staff of the armed forces. On March 2, 2009, soldiers killed Vieira at his residence. The patterns of political instability have continued, with nine successful or attempted coups occurring between 1980 and 2023.
The Balanta constitute the largest ethnic group, comprising approximately 30 percent of the population according to census data. The Fula represent roughly 20 percent, concentrated primarily in the northeastern Gabú region and parts of the north. The Manjaco live predominantly in the northwest. The Mandinka inhabit eastern zones near the border with Guinea and Senegal. The Papel occupy areas around Bissau and Biombo region. The Bijagó people live almost exclusively in the Bissagos Archipelago, maintaining matrilineal social structures distinct from mainland groups. Other groups include the Mancanha, Beafada, and Felupe. Each ethnic group retains distinct languages, though multilingualism is common in urban centers and border zones.
Portuguese remains the sole official language, used in government, education, and formal settings. Kriol serves as the lingua franca, spoken by an estimated 90 percent of the population. Kriol developed as a Portuguese-based creole incorporating vocabulary and structures from Mandinka, Balanta, Manjaco, and other local languages. Each ethnic group maintains its own language for internal community use. Balanta lacks a standardized written form despite being spoken by the country's largest ethnic group. Fula, called Pular locally, connects speakers with the broader Fula linguistic community across the Sahel. Radio broadcasts occur in Portuguese, Kriol, and major ethnic languages. Educational instruction proceeds in Portuguese, though many children arrive at school speaking only Kriol or ethnic languages.