The University of South Africa (UNISA), known colloquially as Unisa, is the largest university system in South Africa by enrollment. It attracts a third of all higher education students in South Africa. Through various colleges and affiliates, UNISA has over 400,000 students, including international students from 130 countries worldwide, making it one of the world's mega universities and the only such university in Africa. As a comprehensive university, Unisa offers both vocational and academic programmes, many of which have received international accreditation, as well as an extensive geographical footprint, giving their students recognition and employability in many countries the world over. The university lists many notable South Africans among its alumni, including two Nobel prize winners: Nelson Mandela, the first democratically elected president of South Africa and Archbishop Desmond Tutu. Founded in 1873 as the University of the Cape of Good Hope, the University of South Africa (or Unisa as it is commonly known) spent most of its early history as an examining agency for Oxford and Cambridge universities and as an incubator from which most other universities in South Africa are descended. Legislation in 1916 established the autonomous University of South Africa (the same legislation established Stellenbosch University and the University of Cape Town as autonomous universities) as an "umbrella" or federal institution with its seat in Pretoria, playing an academic trusteeship role for several colleges that eventually became autonomous universities. The colleges that were under UNISA's trusteeship were Grey University College (Bloemfontein), Huguenot University College (Wellington), Natal University College (Pietermaritzburg), Rhodes University College (Grahamstown), Transvaal University College (Pretoria), the South African School of Mines and Technology (Johannesburg), and Potchefstroom University College. In 1959, with the passage of the Extension of University Education Act, UNISA's trusteeship also extended to the five "black universities", namely University of Zululand, University of the Western Cape, University of the North, University of Durban-Westville, and University of Fort Hare. In 1946, UNISA was given a new role as a distance education university, and today it offers certificate, diploma and degree courses up to doctoral level. In January 2004, Unisa merged with Technikon Southern Africa (Technikon SA, a polytechnic) and incorporated the distance education component of Vista University (VUDEC). The combined institution retained the name University of South Africa. It is now organised by college and by school; see below. The university Location Unisa's Muckleneuk Campus is located in Pretoria and is a major landmark