Nelson Rolihlahla Mandela, born 18 July 1918, served as President of South Africa from 1994 to 1999, the first South-African president to be elected in a fully representative democratic election. Before his presidency, Mandela was an anti-apartheid activist, and the leader of the African National Congress's armed wing Umkhonto we Sizwe. The South African courts convicted him on charges of sabotage, as well as other crimes committed while he led the movement against apartheid. In accordance with his conviction's sentence, Mandela served 27 years in prison, spending many of these years on Robben Island. Following his release from prison on 11 February 1990, Mandela supported reconciliation and negotiation, and helped lead the transition towards multi-racial democracy in South Africa.

Since the end of apartheid, many have frequently praised Mandela, including former opponents. In South Africa he is often known as Madiba, an honorary title adopted by elders of Mandela's clan. The title has come to be synonymous with Nelson Mandela. Mandela has received more than 250 awards over four decades, most notably the 1993 Nobel Peace Prize. In November 2009, the United Nations General Assembly announced that Mandela's birthday, 18 July, is to be known as 'Mandela Day' to mark his contribution to world freedom.

Mandela belongs to a cadet branch of the Thembu dynasty, which reigns in the Transkeian Territories of South Africa's Cape Province. He was born in Mvezo, a small village located in the district of Umtata, the Transkei capital. His patrilineal great-grandfather Ngubengcuka (who died in 1832), ruled as the Inkosi Enkhulu, orking, of the Thembu people. One of the king's sons, named Mandela, became Nelson's grandfather and the source of his surname. However, because he was only the Inkosi's child by a wife of the Ixhiba clan (the so-called "Left-Hand House"), the descendants of his branch of the royal family were not eligible to succeed to the Thembu throne. Mandela's father, Gadla Henry Mphakanyiswa, served as chief of the town of Mvezo. However, upon alienating the colonial authorities, they deprived Mphakanyiswa of his position, and moved his family to Qunu. Despite this, Mphakanyiswa remained a member of the Inkosi's Privy Council, and served an instrumental role in Jongintaba Dalindyebo's ascension to the Thembu throne. Dalindyebo would later return the favour by informally adopting Mandela upon Mphakanyiswa's death. Mandela's father had four wives, with whom he fathered a total of thirteen children (four boys and nine girls). Mandela was born to his third wife ('third' by a complex royal ranking system), Nosekeni Fanny. Fanny was a daughter of Nkedama of the Mpemvu Xhosa clan, the dynastic Right Hand House, in whose umzi or homestead Mandela spent much of his childhood. His given name Rolihlahla means "to pull a branch of a tree", or more colloquially, "troublemaker". Rolihlahla Mandela became the first member of his family to attend a school, where his teacher Miss Mdingane gave him the English name "Nelson". When Mandela was nine, his father died of tuberculosis, and the regent, Jongintaba, became his guardian. Mandela attended a Wesleyan mission school located next to the palace of the regent. Following Thembu custom, he was initiated at age sixteen, and attended Clarkebury Boarding Institute. Mandela completed his Junior Certificate in two years, instead of the usual three. Designated to inherit his father's position as a privy councillor, in 1937 Mandela moved to Healdtown, the Wesleyan college in Fort Beaufort which most Thembu royalty attended. At nineteen, he took an interest in boxing and running at the school.

After enrolling, Mandela began to study for a Bachelor of Arts at the Fort Hare University, where he met Oliver Tambo. Tambo and Mandela became lifelong friends and colleagues. Mandela also became close friends with his kinsman, Kaiser ("K.D.") Matanzima who, as royal scion of the Thembu Right Hand House, was in line for the throne of Transkei, a role that would later lead him to embrace Bantustan policies. His support of these policies would place him and Mandela on opposing political sides. At the end of Nelson's first year, he became involved in a Students' Representative Council boycott against university policies, and was told to leave Fort Hare and not return unless he accepted election to the SRC. Later in his life, while in prison, Mandela studied for a Bachelor of Laws from the University of London External Programme.

Shortly after leaving Fort Hare, Jongintaba announced to Mandela and Justice (the regent's son and heir to the throne) that he had arranged marriages for both of them. The young men, displeased by the arrangement, elected to relocate to Johannesburg. Upon his arrival, Mandela initially found employment as a guard at a mine. However, the employer quickly terminated Mandela after learning that he was the Regent's runaway ward. Mandela later started work as an articled clerk at a Johannesburg law firm, Witkin, Sidelsky and Edelman, through connections with his friend and mentor, realtor Walter Sisulu. While working at Witkin, Sidelsky and Edelman, Mandela completed his B.A. degree at the University of South Africa via correspondence, after which he began law studies at the University of Witwatersrand, where he first befriended fellow students and future anti-apartheid political activists Joe Slovo, Harry Schwarz and Ruth First. Slovo would eventually become Mandela's Minister of Housing, while Schwarz would become his Ambassador to Washington. During this time, Mandela lived in Alexandra township, north of Johannesburg.

After the 1948 election victory of the Afrikaner-dominated National Party, which supported the apartheid policy of racial segregation, Mandela began actively participating in politics. He led prominently in the ANC's 1952 Defiance Campaign and the 1955 Congress of the People, whose adoption of the Freedom Charter provided the fundamental basis of the anti-apartheid cause. During this time, Mandela and fellow lawyer Oliver Tambo operated the law firm of Mandela and Tambo, providing free or low-cost legal counsel to many blacks who lacked attorney representation. Mahatma Gandhi influenced Mandela's approach, and subsequently the methods of succeeding generations of South African anti-apartheid activists. Mandela even took part in the 29–30 January 2007 conference in New Delhi marking the 100th anniversary of Gandhi's introduction of satyagraha (non-violent resistance) in South Africa. Initially committed to nonviolent resistance, Mandela and 150 others were arrested on 5 December 1956 and charged with treason. The marathon Treason Trial of 1956–1961 followed, with all defendants receiving acquittals. From 1952–1959, a new class of black activists known as the Africanists disrupted ANC activities in the townships, demanding more drastic steps against the National Party regime. The ANC leadership under Albert Luthuli, Oliver Tambo and Walter Sisulu felt not only that the Africanists were moving too fast but also that they challenged their leadership. The ANC leadership consequently bolstered their position through alliances with small White, Coloured, and Indian political parties in an attempt to give the appearance of wider appeal than the Africanists. The Africanists ridiculed the 1955 Freedom Charter Kliptown Conference for the concession of the 100,000-strong ANC to just a single vote in a Congressional alliance. Four secretaries-general of the five participating parties secretly belonged to the reconstituted South African Communist Party (SACP), strongly adhering to the Moscow line. In 2003 Blade Nzimande, the SACP General Secretary, revealed that Walter Sisulu, the ANC Secretary-General, secretly joined the SACP in 1955 which meant all five Secretaries General were SACP and thus explains why Sisulu relegated the ANC from a dominant role to one of five equals. In 1959, the ANC lost its most militant support when most of the Africanists, with financial support from Ghana and significant political support from the Transvaal-based Basotho, broke away to form the Pan Africanist Congress (PAC) under the direction of Robert Sobukwe and Potlako Leballo.

In 1961, Mandela became leader of the ANC's armed wing, Umkhonto we Sizwe (translated Spear of the Nation, and also abbreviated MK), which he co-founded. He coordinated sabotage campaigns against military and government targets, making plans for a possible guerrilla war if the sabotage failed to end apartheid. Mandela also raised funds for MK abroad and arranged for paramilitary training of the group. Fellow ANC member Wolfie Kadesh explains the bombing campaign led by Mandela: "When we knew that we going to start on 16 December 1961, to blast the symbolic places of apartheid, like pass offices, native magistrates courts, and things like that ... post offices and ... the government offices. But we were to do it in such a way that nobody would be hurt, nobody would get killed." Mandela said of Wolfie: "His knowledge of warfare and his first hand battle experience were extremely helpful to me." Mandela described the move to armed struggle as a last resort; years of increasing repression and violence from the state convinced him that many years of non-violent protest against apartheid had not and could not achieve any progress. Later, mostly in the 1980s, MK waged a guerrilla war against the apartheid regime in which many civilians became casualties. Mandela later admitted that the ANC, in its struggle against apartheid, also violated human rights, sharply criticising those in his own party who attempted to remove statements supporting this fact from the reports of the Truth and Reconciliation Commission. Up until July 2008, Mandela and ANC party members were barred from entering the United States — except the United Nations headquarters in Manhattan — without a special waiver from the US Secretary of State, because of their South African apartheid regime era designation as terrorists.

On 5 August 1962 Mandela was arrested after living on the run for seventeen months, and was imprisoned in the Johannesburg Fort. The arrest was made possible because the U.S. Central Intelligence Agency (CIA) tipped off the security police as to Mandela's whereabouts and disguise. Three days later, the charges of leading workers to strike in 1961 and leaving the country illegally were read to him during a court appearance. On 25 October 1962, Mandela was sentenced to five years in prison. Two years later on 11 June 1964, a verdict had been reached concerning his previous engagement in the African National Congress (ANC). While Mandela was imprisoned, police arrested prominent ANC leaders on 11 July 1963, at Liliesleaf Farm, Rivonia, north of Johannesburg. Mandela was brought in, and at the Rivonia Trial they were charged by the chief prosecutor Dr. Percy Yutar with the capital crimes of sabotage (which Mandela admitted) and crimes which were equivalent to treason, but easier for the government to prove. The second charge accused the defendants of plotting a foreign invasion of South Africa, which Mandela denied. In his statement from the dock at the opening of the defence case in the trial on 20 April 1964 at Pretoria Supreme Court, Mandela laid out the reasoning in the ANC's choice to use violence as a tactic. His statement described how the ANC had used peaceful means to resist apartheid for years until the Sharpeville Massacre. That event coupled with the referendum establishing the Republic of South Africa and the declaration of a state of emergency along with the banning of the ANC made it clear to Mandela and his compatriots that their only choice was to resist through acts of sabotage and that doing otherwise would have been tantamount to unconditional surrender. Mandela went on to explain how they developed the Manifesto of Umkhonto we Sizwe on 16 December 1961 intent on exposing the failure of the National Party's policies after the economy would be threatened by foreigners' unwillingness to risk investing in the country. He closed his statement with these words:

Bram Fischer, Vernon Berrange, Harry Schwarz, Joel Joffe, Arthur Chaskalson and George Bizos were part of the defence team that represented the accused. Harold Hanson was brought in at the end of the case to plead mitigation. All except Rusty Bernstein were found guilty, but they escaped the gallows and were sentenced to life imprisonment on 12 June 1964.

Nelson Mandela was imprisoned on Robben Island where he remained for the next eighteen of his twenty-seven years in prison. While in jail, his reputation grew and he became widely known as the most significant black leader in South Africa. On the island, he and others performed hard labour in a lime quarry. Prison conditions were very basic. Prisoners were segregated by race, with black prisoners receiving the fewest rations. Political prisoners were kept separate from ordinary criminals and received fewer privileges. Mandela describes how, as a D-group prisoner (the lowest classification) he was allowed one visitor and one letter every six months. Letters, when they came, were often delayed for long periods and made unreadable by the prison censors. Whilst in prison Mandela undertook study with the University of London by correspondence through its External Programme and received the degree of Bachelor of Laws. He was subsequently nominated for the position of Chancellor of the University of London in the 1981 election, but lost to Princess Anne.

In his 1981 memoir Inside BOSS secret agent Gordon Winter describes his involvement in a plot to rescue Mandela from prison in 1969: this plot was infiltrated by Winter on behalf of South African intelligence, who wanted Mandela to escape so they could shoot him during recapture. The plot was foiled by British Intelligence.

In March 1982 Mandela was transferred from Robben Island to Pollsmoor Prison, along with other senior ANC leaders Walter Sisulu, Andrew Mlangeni, Ahmed Kathrada and Raymond Mhlaba. It was speculated that this was to remove the influence of these senior leaders on the new generation of young black activists imprisoned on Robben Island, the so-called "Mandela University". However, National Party minister Kobie Coetsee says that the move was to enable discreet contact between them and the South African government. In February 1985 President P.W. Botha offered Mandela conditional release in return for renouncing armed struggle. Coetsee and other ministers had advised Botha against this, saying that Mandela would never commit his organisation to giving up the armed struggle in exchange for personal freedom. Mandela indeed spurned the offer, releasing a statement via his daughter Zindzi saying "What freedom am I being offered while the organisation of the people remains banned? Only free men can negotiate. A prisoner cannot enter into contracts." The first meeting between Mandela and the National Party government came in November 1985 when Kobie Coetsee met Mandela in Volks Hospital in Cape Town where Mandela was recovering from prostate surgery. Over the next four years, a series of tentative meetings took place, laying the groundwork for further contact and future negotiations, but little real progress was made. In 1988 Mandela was moved to Victor Verster Prison and would remain there until his release. Various restrictions were lifted and people such as Harry Schwarz were able to visit him. Schwarz, a friend of Mandela, had known him since university when they were in the same law class. He was also a defense barrister at the Rivonia Trial and would become Mandela's ambassador to Washington during his presidency.

Throughout Mandela's imprisonment, local and international pressure mounted on the South African government to release him, under the resounding slogan Free Nelson Mandela! In 1989, South Africa reached a crossroads when Botha suffered a stroke and was replaced as president by Frederik Willem de Klerk. De Klerk announced Mandela's release in February 1990. Nelson Mandela was visited several times by delegates of the International Committee of the Red Cross, while at Robben Island and later at Pollsmoor prison. On 2 February 1990, State President F.W. de Klerk reversed the ban on the ANC and other anti-apartheid organisations, and announced that Mandela would shortly be released from prison. Mandela was released from Victor Verster Prison in Paarl on 11 February 1990. The event was broadcast live all over the world. On the day of his release, Mandela made a speech to the nation. He declared his commitment to peace and reconciliation with the country's white minority, but made it clear that the ANC's armed struggle was not yet over:

He also said his main focus was to bring peace to the black majority and give them the right to vote in both national and local elections.

Following his release from prison, Mandela returned to the leadership of the ANC and, between 1990 and 1994, led the party in the multi-party negotiations that led to the country's first multi-racial elections. In 1991, the ANC held its first national conference in South Africa after its unbanning, electing Mandela as President of the organisation. His old friend and colleague Oliver Tambo, who had led the organisation in exile during Mandela's imprisonment, became National Chairperson. Mandela's leadership through the negotiations, as well as his relationship with President F.W. de Klerk, was recognised when they were jointly awarded the Nobel Peace Prize in 1993. However, the relationship was sometimes strained, particularly so in a sharp exchange in 1991 when he furiously referred to De Klerk as the head of "an illegitimate, discredited, minority regime". The talks broke down following the Boipatong massacre in June 1992 when Mandela took the ANC out of the negotiations, accusing De Klerk's government of complicity in the killings. However, talks resumed following the Bisho massacre in September 1992, when the spectre of violent confrontation made it clear that negotiations were the only way forward.

Following the assassination of ANC leader Chris Hani in April 1993, there were renewed fears that the country would erupt in violence. Mandela addressed the nation appealing for calm, in a speech regarded as 'presidential' even though he was not yet president of the country at that time:

While some riots did follow the assassination, the negotiators were galvanised into action, and soon agreed that democratic elections should take place on 27 April 1994, just over a year after Hani's assassination.

South Africa's first multi-racial elections in which full enfranchisement was granted were held on 27 April 1994. The ANC won 62% of the votes in the election, and Mandela, as leader of the ANC, was inaugurated on 10 May 1994 as the country's first black President, with the National Party's de Klerk as his first deputy and Thabo Mbeki as the second in the Government of National Unity. As President from May 1994 until June 1999, Mandela presided over the transition from minority rule and apartheid, winning international respect for his advocacy of national and international reconciliation. Mandela encouraged black South Africans to get behind the previously hated Springboks (the South African national rugby team) as South Africa hosted the 1995 Rugby World Cup. (This is the theme of the 2009 film Invictus.) After the Springboks won an epic final over New Zealand, Mandela presented the trophy to captain Francois Pienaar, an Afrikaner, wearing a Springbok shirt with Pienaar's own number 6 on the back. This was widely seen as a major step in the reconciliation of white and black South Africans.

After assuming the presidency, one of Mandela's trademarks was his use of Batik shirts, known as "Madiba shirts", even on formal occasions. In South Africa's first post-apartheid military operation, Mandela ordered troops into Lesotho in September 1998 to protect the government of Prime Minister Pakalitha Mosisili. This came after a disputed election prompted fierce opposition threatening the unstable government. Commentators and critics including AIDS activists such as Edwin Cameron have criticised Mandela for his government's ineffectiveness in stemming the AIDS crisis. After his retirement, Mandela admitted that he may have failed his country by not paying more attention to the HIV/AIDS epidemic. Mandela has since spoken out on several occasions against the AIDS epidemic.

President Mandela took a particular interest in helping to resolve the long-running dispute between Gaddafi's Libya, on the one hand, and the United States and Britain on the other, over bringing to trial the two Libyans who were indicted in November 1991 and accused of sabotaging Pan Am Flight 103, which crashed at the Scottish town of Lockerbie on 21 December 1988, with the loss of 270 lives. As early as 1992, Mandela informally approached President George H.W. Bush with a proposal to have the two indicted Libyans tried in a third country. Bush reacted favourably to the proposal, as did President François Mitterrand of France and King Juan Carlos I of Spain. In November 1994 – six months after his election as president – Mandela formally proposed that South Africa should be the venue for the Pan Am Flight 103 bombing trial. However, British Prime Minister, John Major, flatly rejected the idea saying the British government did not have confidence in foreign courts. A further three years elapsed until Mandela's offer was repeated to Major's successor, Tony Blair, when the president visited London in July 1997. Later the same year, at the 1997 Commonwealth Heads of Government Meeting (CHOGM) at Edinburgh in October 1997, Mandela warned: "No one nation should be complainant, prosecutor and judge." A compromise solution was then agreed for a trial to be held at Camp Zeist in the Netherlands, governed by Scots law, and President Mandela began negotiations with Colonel Gaddafi for the handover of the two accused (Megrahi and Fhimah) in April 1999. At the end of their nine-month trial, the verdict was announced on 31 January 2001. Fhimah was found not guilty but Megrahi was convicted and sentenced to 27 years in a Scottish jail. Megrahi's initial appeal was turned down in March 2002, and former president Mandela went to visit him in Barlinnie prison on 10 June 2002. 'Megrahi is all alone', Mandela told a packed press conference in the prison's visitors room. 'He has nobody he can talk to. It is psychological persecution that a man must stay for the length of his long sentence all alone. It would be fair if he were transferred to a Muslim country — and there are Muslim countries which are trusted by the West. It will make it easier for his family to visit him if he is in a place like the kingdom of Morocco, Tunisia or Egypt.' Megrahi was subsequently moved to Greenock jail and out of solitary confinement. In August 2009 Megrahi, suffering from cancer and expected to have only 3 months left to live, was released on compassionate grounds and allowed to return to Libya. The Nelson Mandela Foundation expressed its support for the decision to release Megrahi in a letter sent to the Scottish Government on behalf of Mandela.

Mandela has been married three times, has fathered six children, has twenty grandchildren, and a growing number of great-grandchildren. He is grandfather to Chief Mandla Mandela. Mandela's first marriage was to Evelyn Ntoko Mase who, like Mandela, was also from what later became the Transkei area of South Africa, although they actually met in Johannesburg. The couple broke up in 1957 after 13 years, divorcing under the multiple strains of his constant absences, devotion to revolutionary agitation, and the fact she was a Jehovah's Witness, a religion which requires political neutrality. Evelyn Mase died in 2004. The couple had two sons, Madiba Thembekile (Thembi) (1946–1969) and Makgatho Mandela (1950–2005) , and two daughters, both named Makaziwe Mandela (known as Maki; born 1947 and 1953). Their first daughter died aged nine months, and they named their second daughter in her honour. All their children were educated at the United World College of Waterford Kamhlaba. Thembi was killed in a car crash in 1969 at the age of twenty-five, while Mandela was imprisoned on Robben Island, and Mandela was not allowed to attend the funeral. Makgatho died of AIDS in 2005. Mandela's second wife, Winnie Madikizela-Mandela, also came from the Transkei area, although they, too, met in Johannesburg, where she was the city's first black social worker. They had two daughters, Zenani (Zeni), born 4 February 1958, and Zindziswa (Zindzi) Mandela-Hlongwane, born 1960. Zindzi was only 18 months old when her father was sent to Robben island. Later, Winnie would be deeply torn by family discord which mirrored the country's political strife; while her husband was serving a life sentence on the Robben Island prison, her father became the agriculture minister in the Transkei. The marriage ended in separation (April 1992) and divorce (March 1996), fuelled by political estrangement. Mandela still languished in prison when his daughter Zenani was married to Prince Thumbumuzi Dlamini in 1973, elder brother of King Mswati III of Swaziland. Although she had vivid memories of her father, from the age of four up until sixteen, South African authorities did not permit her to visit him. The Dlamini couple live and run a business in Boston. One of their sons, Prince Cedza Dlamini (born 1976), educated in the United States, has followed in his grandfather's footsteps as an international advocate for human rights and humanitarian aid. Zindzi Mandela-Hlongwane made history worldwide when she read out Mandela's speech refusing his conditional pardon in 1985. She is a businesswoman in South Africa with three children, the eldest of whom is a son, Zondwa Gadaffi Mandela. Mandela was remarried, on his 80th birthday in 1998, to Graça Machel née Simbine, widow of Samora Machel, the former Mozambican president and ANC ally who was killed in an air crash 12 years earlier. The wedding followed months of international negotiations to set the unprecedented bride-price to be remitted to Machel's clan. Said negotiations were conducted on Mandela's behalf by his traditional sovereign, King Buyelekhaya Zwelibanzi Dalindyebo. The paramount chief's grandfather was the regent Jongintaba Dalindyebo, who had arranged a marriage for Mandela, which he eluded by fleeing to Johannesburg in 1940.

Mandela became the oldest elected President of South Africa when he took office at the age of 75 in 1994. He decided not to stand for a second term and retired in 1999, to be succeeded by Thabo Mbeki. After his retirement as President, Mandela went on to become an advocate for a variety of social and human rights organisations. He has expressed his support for the international Make Poverty History movement of which the ONE Campaign is a part. The Nelson Mandela Invitational charity golf tournament, hosted by Gary Player, has raised over twenty million rand for children's charities since its inception in 2000. This annual special event has become South Africa's most successful charitable sports gathering and benefits both the Nelson Mandela Children's Fund and Gary Player Foundation equally for various children's causes around the world. Mandela is a vocal supporter of SOS Children's Villages, the world's largest organisation dedicated to raising orphaned and abandoned children. Mandela appeared in a televised advertisement for the 2006 Winter Olympics, and was quoted for the International Olympic Committee's Celebrate Humanity campaign:

For seventeen days, they are roommates. For seventeen days, they are soulmates. And for twenty-two seconds, they are competitors. Seventeen days as equals. Twenty-two seconds as adversaries. What a wonderful world that would be. That's the hope I see in the Olympic Games.