Rhodesia's Unilateral Declaration of Independence in the context of "Rhodesia"

A unilateral declaration of independence (UDI) or "unilateral secession" is a formal process leading to the establishment of a new state by a subnational entity which declares itself independent and sovereign without a formal agreement with the state from which it is seceding. The term was first used when Rhodesia declared independence in 1965 from the United Kingdom (UK) without an agreement with the UK.

Ian Douglas Smith GCLM ID (8 April 1919 – 20 November 2007) was a Rhodesian and later Zimbabwean politician, farmer, and fighter pilot who served as Prime Minister of Rhodesia (known as Southern Rhodesia until October 1964 and now known as Zimbabwe) from 1964 to 1979. He was the country's first leader to be born and raised in Rhodesia, and led the predominantly white government that unilaterally declared independence from the United Kingdom in November 1965 in opposition to their demands for the implementation of majority rule as a condition for independence. His 15 years in power were defined by the country's international isolation and involvement in the Rhodesian Bush War, which pitted the Rhodesian Security Forces against the Soviet and Chinese-funded military wings of the Zimbabwe African National Union (ZANU) and Zimbabwe African People's Union (ZAPU).

Smith was born to British settlers in the small town of Selukwe located in the Southern Rhodesian Midlands, four years before the colony became self-governing in 1923. During the Second World War, he served as a Royal Air Force fighter pilot, where a crash in Egypt resulted in facial and bodily wounds that remained conspicuous for the rest of his life. Following recovery, he served in Europe, where he was shot down and subsequently fought alongside Italian partisans. After the war, he established a farm in his hometown in 1948 and became a Member of Parliament for Selukwe that year. Originally a member of the Liberal Party, he defected to the United Federal Party in 1953, and served as Chief Whip from 1958 onwards. He left that party in 1961 in protest over the territory's new constitution, and went on to co-found the Rhodesian Front the following year.

The Lancaster House Agreement is an agreement signed on 21 December 1979 in Lancaster House, following the conclusion of a constitutional conference where different parties discussed the future of Zimbabwe Rhodesia, formerly known as Rhodesia. The agreement effectively concluded the Rhodesian Bush War. It also marked the nullification of Rhodesia's Unilateral Declaration of Independence, as British colonial authority was to be restored for a transitional period to internationally recognised independence, during which free elections under supervision by the British government would take place. Crucially, ZANU and ZAPU, the political wings of ZANLA and ZIPRA (who had been waging an escalating insurgency since 1964), 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.

Public holidays in Rhodesia, a historical region in southern Africa equivalent to today's Zimbabwe and Zambia—formerly Southern and Northern Rhodesia, respectively—were largely based around milestones in the region's short history. Annual holidays marked various aspects of the arrival of white people during the 1880s and 1890s, as well as the respective unilateral declarations of independence (1965) and of republican government (1970). On these days, most businesses and non-essential services closed. A number of Christian holidays were also observed according to custom, in the traditional British manner, and referred to in official documents by name—Christmas Day, for example, or Easter Monday.

Rhodesian non-work days were first defined in 1895, by The Bills of Exchange Regulations passed by Leander Starr Jameson, the second administrator of the territory appointed by the British South Africa Company. Holidays were instituted along traditional British lines, with some others created exclusively for Rhodesia: Shangani Day, on 4 December, marked the anniversary of the Shangani Patrol being killed in battle, while Rhodes's Day and Founders' Day—respectively commemorating Company chief Cecil Rhodes and his contemporaries—were held consecutively, starting on the first or second Monday of each July, to create the annual four-day "Rhodes and Founders' weekend". Shangani Day was replaced as a public holiday by Occupation Day in 1920, but continued to be unofficially marked thereafter. Occupation Day, held on 12 September each year, marked the anniversary of the arrival of the Pioneer Column at Fort Salisbury in 1890, and their raising of the Union Jack on the kopje overlooking the site. It was renamed Pioneers' Day in 1961.

Zimbabwe Rhodesia (/zɪmˈbɑːbweɪ roʊˈdiːʒə, zɪmˈbɑːbwi roʊˈdiːʒə/), alternatively known as Zimbabwe-Rhodesia, also informally known as Zimbabwe or Rhodesia, was a short-lived unrecognised sovereign state that existed from 1 June 1979 to 18 April 1980, though it lacked international recognition. Zimbabwe Rhodesia was preceded by another state named the Republic of Rhodesia and was briefly under a British-supervised transitional government sometimes referred to as a reestablished Southern Rhodesia, which according to British constitutional theory had remained the lawful government in the area after Unilateral Declaration of Independence (UDI) in 1965. Following the 1980 Southern Rhodesian general election, the country was granted internationally-recognized independence within the Commonwealth as the Republic of Zimbabwe.