Public holidays in Rhodesia 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. Southern Rhodesia effectively became the entirety of Rhodesia in 1964 when Northern Rhodesia became independent as Zambia. After Southern Rhodesia's colonial government unilaterally declared independence from Britain on 11 November 1965, the anniversary became celebrated as
Southern Rhodesia Treaty, which was signed by King Lobengula of the Ndebele people. "Southern" was first used in 1898 and dropped from normal usage in 1964, on the break-up of the Federation of Rhodesia and Nyasaland. "Rhodesia" then remained the name of the country until the creation of Zimbabwe Rhodesia in 1979. Legally, from the British perspective, the name Southern Rhodesia continued to be used until 18 April 1980, when the Republic of Zimbabwe was promulgated. The British government agreed that Rhodes' company, the British South Africa Company (BSAC), would administer the territory stretching from the Limpopo to Lake Tanganyika under charter