The Zimbabwe African National Union was a political party during the struggle for Rhodesia's, ultimately Zimbabwe's, independence, formed as a split from ZAPU. It won the 1980 elections under the leadership of Robert Mugabe, and eight years later merged again with Joshua Nkomo's ZAPU to form Zanu-PF, the current governing party of the country.
Its founder was the Reverend Ndabaningi Sithole (1920-2000) in conjunction with an able, activist, black lawyer Herbert Chitepo, who were dissatisfied with the militant tactics of Nkomo. In contrast to future developments, both parties drew from both the Shona and the Ndebele - the two major tribes of the region. Both ZANU and ZAPU formed political wings within the country (under those names) and military wings: the Zimbabwe African National Liberation Army (ZANLA) and the Zimbabwe People's Revolutionary Army (ZIPRA) respectively to fight the struggle from neighbouring countries - ZANLA from Mozambique after the Portuguese withdrew, and ZIPRA from Zambia and other countries.
After Chitepo's assassination on 18th March, 1975, Robert Mugabe, in Mozambique at the time, unilaterally assumed control of ZANU. Later that year there was a factional split along tribal lines caused the Ndebele to follow Sitole into the moderate Zanu (Ndonga) party, who renounced violent struggle, while the Shona followed Mugabe with a more militant agenda.
Sithole joined a transitional government of whites and blacks in 1979, led by Bishop Abel Muzorewa. When sanctions remained in place, he joined Muzorewa for the Lancaster House Agreement in London, where a new constitution and elections were prepared. His small breakaway opposition group failed to win any seats in independent elections that swept Mugabe under the ZANU flag to power in 1980.
In 1988 after 8 years of low-level civil war termed Gukurahundi, the opposition Zimbabwe African People's Union (ZAPU), led by Joshua Nkomo, merged with ZANU to form Zanu-PF with the added moniker of Patriotic Front, in what was seen as a step towards a one party state.