The rivers of Guinea and the islands of Cape Verde were among the first
areas in Africa explored by the Portuguese in the 15th century.
Portugal claimed Portuguese Guinea in 1446, but few trading posts were
established before 1600. In 1630, a "captaincy-general" of Portuguese
Guinea was established to administer the territory. With the
cooperation of some local tribes, the Portuguese entered the slave trade
and exported large numbers of Africans to the Western Hemisphere via the
Cape Verde Islands. Cacheu became one of the major slave centers, and a
small fort still stands in the town. The slave trade declined in the
19th century, and Bissau, originally founded as a military and slave-
trading center in 1765, grew to become the major commercial center.
Portuguese conquest and consolidation of the interior did not begin
until the latter half of the 19th century. Portugal lost part of Guinea
to French West Africa (including the center of earlier Portuguese
commercial interest, the Casamance River region). A dispute with Great
Britain over the island of Bolama was settled in Portugal's favor with
the involvement of U.S. President Ulysses S. Grant.
Before World War I, Portuguese forces under Maj. Teixeira Pinto, with
some assistance from the Muslim population, subdued animist tribes and
eventually established the territory's borders. The interior of
Portuguese Guinea was brought under control after more than 30 years of
fighting; final subjugation of the Bijagos Islands did not occur until
1936. The administrative capital was moved from Bolama to Bissau in
1941, and in 1952, by constitutional amendment, the colony of Portuguese
Guinea became an overseas province of Portugal.
In 1956, the African Party for the Independence of Guinea and Cape Verde
(PAIGC) was organized clandestinely by Amilcar Cabral and Raphael
Barbosa. The PAIGC moved its headquarters to Conakry, Guinea, in 1960
and started an armed rebellion against the Portuguese in 1961.
Despite the presence of Portuguese troops, which grew to more than
35,000, the PAIGC steadily expanded its influence until, by 1968, it
controlled most of the country. It established civilian rule in the
territory under its control and held elections for a National Assembly.
Portuguese forces and civilians increasingly were confined to their
garrisons and larger towns. The Portuguese Governor and Commander-in-
Chief from 1968 to 1973, Gen. Antonio de Spinola, returned to Portugal
and led the movement which brought democracy to Portugal and
independence for its colonies.
Amilcar Cabral was assassinated in Conakry in 1973, and party leadership
fell to Aristides Pereira, who later became the first president of the
Republic of Cape Verde. The PAIGC National Assembly met at Boe in the
southeastern region and declared the independence of Guinea-Bissau on
September 24, 1973. Following Portugal's April 1974 revolution, it
granted independence to Guinea-Bissau on September 10, 1974. The United
States recognized the new nation that day. Luis Cabral, Amilcar
Cabral's half-brother, became President of Guinea-Bissau. In late 1980,
the government was overthrown in a relatively bloodless coup led by
Prime Minister and former armed forces commander Joao Bernardo Vieira.
From November 1980 to May 1984, power was held by a provisional
government responsible to a Revolutionary Council headed by President
Joao Bernardo Vieira. In 1984, the council was dissolved, and the 150-
member National Popular Assembly (ANP) was reconstituted. The single-
party assembly approved a new constitution, elected President Vieira to
a new 5-year term, and elected a Council of State, which is the
executive agent of the ANP. Under this system, the president presides
over the Council of State and serves as head of state and government.
The president is also head of the PAIGC and commander in chief of the
armed forces.
There were alleged coup plots against the Vieira Government in 1983,
1985, and 1993. In 1986, first Vice President Paulo Correia and five
others were executed for treason following a lengthy trial.

source: U.S. State Department Background Notes 1994