The Lancaster House Agreement, signed on 21 December 1979, declared a ceasefire, ending the Rhodesian Bush War; and directly led to Rhodesia achieving internationally recognised independence as Zimbabwe. It required the full resumption of direct British rule, nullifying the Unilateral Declaration of Independence of 1965. British governance would be strictly prescribed to the duration of a proposed election period followed by a formal power transfer back to a recognised, sovereign state. Constitutional instruments would thus be transferred from the British state to a popularly elected government, under an unqualified universal franchise vote. Crucially, the political wings of the black nationalist groups ZANU and ZAPU, who had been waging an increasingly violent insurgency, would be permitted to stand candidates in the forthcoming elections. This was however conditional to compliance with the ceasefire and the verified absence of voter intimidation.
The Agreement would lead to the dissolution of the unrecognised state of Zimbabwe Rhodesia, created months earlier by the Internal Settlement; an agreement forged between moderate black nationalists and Prime Minister Ian Smith's Government. While Zimbabwe Rhodesia remained unrecognised, the Internal Settlement enfranchised the majority of blacks (hitherto the key British demand) and resulted in the election of the country's first black Prime Minister, Bishop Abel Muzorewa.
Lancaster House covered the Independence Constitution, pre-independence arrangements and the terms of ceasefire. The Agreement is named after Lancaster House in London, where the conference on independence from 10 September to 15 December 1979 was held.
The parties represented during the conference were: the British Government, the Patriotic Front led by Robert Mugabe and Joshua Nkomo, ZAPU (Zimbabwe African Peoples Union) and ZANU (Zimbabwe African National Union) and the Zimbabwe Rhodesia Government, represented by Prime Minister, Bishop Abel Muzorewa and Ian Smith, Minister without Portfolio.
Following the Meeting of Commonwealth Heads of Government held in Lusaka from 1–7 August 1979, the British government invited Muzorewa and the leaders of the Patriotic Front to participate in a Constitutional Conference at Lancaster House. The purpose of the Conference was to discuss and reach agreement on the terms of an Independence Constitution, to agree on the holding of elections under British authority, and to enable Zimbabwe Rhodesia to proceed to lawful and internationally recognised independence, with the parties settling their differences by political means.
Lord Carrington, Foreign and Commonwealth Secretary of the United Kingdom, chaired the Conference. The conference took place from 10 September – 15 December 1979 with 47 plenary sessions.
In the course of its proceedings the conference reached agreement on the following issues:
In concluding this agreement and signing its report, the parties undertook:
Under the Independence Constitution agreed, 20 per cent of the seats in the country's parliament were to be reserved for whites. This provision remained in the constitution until 1987.
The agreement as signed on 21 December 1979. Lord Carrington and Sir Ian Gilmour signed the Agreement on behalf of the United Kingdom, Bishop Abel Muzorewa and Dr Silas Mundawarara signed for the Government of Zimbabwe Rhodesia, and Robert Mugabe and Joshua Nkomo for the Patriotic Front.
According to Robert Matthews, the success of the Lancaster House negotiations can be explained by four factors:
Under the terms of the Agreement, Zimbabwe Rhodesia temporarily reverted to its former status as the Colony of Southern Rhodesia, thereby ending the rebellion caused by Rhodesia's Unilateral Declaration of Independence. Lord Soames was appointed Governor with full executive and legislative powers.
In terms of the ceasefire, ZAPU and ZANU guerillas were to gather at designated Assembly Points under British supervision, following which elections were to be held to elect a new government. These elections were held in February 1980, and resulted in the Zimbabwe African National Union - Patriotic Front (ZANU-PF) led by Robert Mugabe winning a majority of seats. Independence in terms of the Constitution agreed to at Lancaster House was granted to Zimbabwe on 18 April 1980 with Robert Mugabe as the first Prime Minister.
In addition to the terms cited above, Robert Mugabe and his supporters were pressured into agreeing to wait ten years before instituting land reform.
The three-month-long conference almost failed to reach an accord due to disagreements on land reform. Mugabe was pressured to sign, and land was the key stumbling block. Both the British and American governments offered to compensate white citizens for any land sold so as to aid reconciliation (the "Willing buyer, Willing seller" principle), and a fund was established to operate from 1980 to 1990.
In 1980, the first phase of land reform, partly funded by the United Kingdom, resettled around 70,000 landless people on more than 20,000 km2 (4,900,000 acres) of land in the new Zimbabwe.
In 1981, the British assisted in setting up a Zimbabwe conference on reconstruction and development, at which more than £630 million of international aid was pledged.
In 1997, war veterans began receiving individual personal payments of ZW$50,000 each for their service in the Rhodesian Bush War, costing the nation's tax payers billions of dollars, and depleting government coffers. Some months later, Robert Mugabe announced that the forced acquisition of land under Section 8 would proceed and, within 24 hours, the local currency had devalued more than 50%. Thus began a period of hyperinflation and the demonetisation of the Zimbabwean currency, accompanied by the "Flight of Whites" from the country, most never to return.
According to an independent newspaper in Zimbabwe, the Lancaster House Agreement has been modified or changed more than 27 times since independence.