FACTBOX-History of the African National Congress

(Reuters) - South Africa's ruling African National Congress chooses its new leader during a December 16-20 congress.

ANC Deputy President Jacob Zuma has taken a commanding lead over party and state President Thabo Mbeki. If Zuma wins he is highly likely to become South Africa's next president in 2009.

Here are some main facts about the ruling ANC.

* ORIGINS:

-- In January 1912 the South African Native National Congress was formed in the central city of Bloemfontein in response to legislation denying political rights to the black population.

-- It changed its name to the African National Congress in 1923. Its early leaders, black professionals, wanted a gradual extension of the electoral franchise on the British model. The party failed to moderate the race policies of successive white governments.

* APARTHEID:

-- The white Afrikaner National Party's electoral victory in 1948 heralded the systematic racial discrimination of apartheid, prompting young radicals like Nelson Mandela and Walter Sisulu to take over the leadership of the ANC.

-- The ANC backed the first systematic campaign against the government in 1952, when thousands of blacks were arrested for defying discriminatory laws. It organized the 1955 "Congress of the People" which adopted the Freedom Charter, calling for a non-racial democracy.

-- The apartheid government banned the ANC in March 1960 after the Sharpeville Massacre when 69 protesters were killed.

* A NEW ERA:

-- The ANC helped stimulate international pressure on Pretoria through sanctions, cultural and sporting boycotts and diplomatic isolation.

-- A government decision in December 1989 to release seven veteran ANC leaders including Sisulu was a sign the government recognized it had to talk with its old adversary.

-- President F.W. de Klerk finally lifted the ban on the ANC in February 1990, and months later the movement suspended its 30-year-old armed struggle against white rule.

-- Nelson Mandela, who had been sentenced to life in prison for conspiracy and sabotage, was freed after 27 years in 1990. He led the ANC to victory in the first all-race election in 1994.

-- Mbeki replaced Mandela as head of the ANC in 1997, and was elected South Africa's second black president in 1999. In 2002 Mbeki was elected to lead the ANC for another five years, and he again led the party at the 2004 election.

* PARTY SPLIT:

-- The rivalry between Mbeki and Zuma has plunged the party into one of the worst crises in its history. Mbeki sacked Zuma as his deputy in 2005 after he was implicated in a graft trial.

(Writing by David Cutler, London Editorial Reference Unit)