Nelson Rolihlahla Mandela was born on 18 July 1918 in the small village of Mvezo, on the Mbashe River, district of Umtata in Transkei, South Africa. His Father named him Rolihlahla, which means "pulling the branch of the tree", or more colloquially "troublemaker." The name Nelson was not given until his first day at school.
Nelson Mandela's father, Gadla Henry Mphakanyiswa, was the chief "by blood and custom" of Mvezo, a position confirmed by the paramount chief of the Thembu, Jongintaba Dalindyebo. Although the family is descended from Thembu royalty (one of Mandela's ancestors was paramount chief in the 18th century) the line had passed down to Mandela through lesser 'Houses', rather than through a line of potential succession. The clan name of Madiba, which is often used as a form of address for Mandela, comes from the ancestral chief.
Until the advent of European domination in the region, chieftaincy of the Thembu (and other tribes of the Xhosa nation) was by patrimonial decent, with the first son of the major wife (known as the Great House) becoming automatic heir, and the first son of the second wife (the highest of the lessor wives, also known as the Right Hand House) being relegated to creating a minor chiefdom. The sons of the third wife (known as the Left Hand House) were destined to become advisors to the chief.
Nelson Mandela was the son of the third wife, Noqaphi Nosekeni, and could have otherwise expected to become a royal advisor. He was one of thirteen children, and had three elder brothers all of whom were of higher 'rank'. Mandela's mother was a Methodist, and Nelson followed in her footsteps, attending a Methodist missionary school.
When Nelson Mandela's father died in 1930, the paramount chief, Jongintaba Dalindyebo, became his guardian. In 1934, a year during which he attended three month initiation school (during which he was circumcised), Mandela matriculated from Clarkebury Missionary school. Four years later he graduated from Healdtown, a strict Methodist college, and left to pursue higher education at the University of Fort Hare (South Africa's first university college for Black Africans). It was here he first met his lifelong friend and associate Oliver Tambo.
Both Nelson Mandela and Oliver Tambo were expelled from Fort Hare in 1940 for political activism. Briefly returning to Transkei, Mandela discovered that his guardian had arranged a marriage for him. He fled towards Johannesburg, where he obtained work as a night-watchman on a gold mine.
Nelson Mandela moved into a house in Alexandra, a Black suburb of Johannesburg, with his mother. Here he met Walter Sisulu and Walter's fiancée Albertina. Mandela started working as a clerk in a law firm, studying in the evening through a correspondence course with the University of South Africa (now UNISA) to complete his first degree. He was awarded his Bachelor's degree in 1941, and in 1942 he was articled to another firm of attorneys and started upon a law degree at the University of Witwatersrand. Here he worked with a study partner, Seretse Khama, who would later become the first president of an independent Botswana.
In 1944 Nelson Mandela married Evelyn Mase, a cousin of Walter Sisulu. He also began his political career in earnest, joining the African National Congress, ANC. Finding the existing leadership of the ANC to be "a dying order of pseudo-liberalism and conservatism, of appeasement and compromise.", Mandela, along with Tambo, Sisulu, and a few others formed the African National Congress Youth League, ANCYL. In 1947 Mandela was elected as secretary of the ANCYL, and became a member of the Transvaal ANC executive.
By 1948 Nelson Mandela had failed to pass the exams required for his LLB law degree, and he decided instead to settle for the 'qualifying' exam which would allow him to practice as an attorney. When DF Malan's Herenigde Nationale Party (HNP, Re-united National Party) won the 1948 election, Mandela, Tambo, and Sisulu acted. The existing ANC president was pushed out of office and someone more amenable to the ideals of the ANCYL was brought in as a replacement. Walter Sisulu proposed a 'programme of action', which was subsequently adopted by the ANC. Mandela was made president of the Youth League in 1951.