Mbeki was now in a contest to become Mandela's deputy. His rivals were Ramaphosa and Chris Hani, secretary general of the SACP. However, Mbeki had a strong support base among the ANC Youth League and the ANC's Women's League. When Chris Hani was assassinated in 1993, Mbeki and Ramaphosa were left to contest the position of Deputy President. After leaving the Eastern Cape, Thabo Mbeki lived in Johannesburg, working with Walter Sisulu. After the arrest and imprisonment of Sisulu, Mandela and his father—and facing a similar fate—he left South Africa as one of a number of young ANC militants (Umkhonto we Sizwe cadres) sent abroad to continue their education and their anti-apartheid activities. He ultimately spent 28 years in exile, returning to his homeland only after the release of Nelson Mandela. Mbeki spent the early years of his exile in the United Kingdom. In 1962, aged 19, he arrived at the brand-new University of Sussex, earning first a BA degree in economics, and then remaining to complete a Master's degree in African studies. While at Sussex he saw himself as a representative of the ANC and helped motivate the university population against apartheid. Still in the UK, he worked in the ANC's London office on Penton Street. He received military training in the Soviet Union and lived at different times in Botswana, Swaziland and Nigeria, but his primary base was in Lusaka, Zambia, the site of the ANC headquarters. In 1973, Mbeki was sent to Botswana, where he engaged the Botswana government in discussions to open an ANC office there. He left Botswana in 1974. In 1975, he became a member of the National Executive Committee of the ANC. In December 1976, he was sent to Nigeria as a representative of the ANC. While in exile, his brother Jama Mbeki, a supporter of the rival Pan Africanist Congress, was killed by agents of the Lesotho government in 1982 while attempting to assist the Lesotho Liberation Army. His son Kwanda, the product of a liaison in Mbeki's teenage years, was killed while trying to leave South Africa to join his father. When Mbeki finally was able to return home to South Africa and was reunited with his own father, the elder Mbeki told a reporter, "You must remember that Thabo Mbeki is no longer my son. He is my comrade!" A news article pointed out that this was an expression of pride, explaining, "For Govan Mbeki, a son was a mere biological appendage; to be called a comrade, on the other hand, was the highest honour."