Botswana, officially the Republic of Botswana, is a landlocked country in Southern Africa. Formerly the British protectorate of Bechuanaland, Botswana adopted its name after becoming independent within the Commonwealth on 30 September 1966. Since then, it has been a representative republic, with a consistent record of uninterrupted democratic elections and the lowest perceived corruption ranking in Africa since at least 1998. It is currently Africa's oldest continuous democracy. Botswana is topographically flat, with up to 70 percent of its territory being the Kalahari Desert. It is bordered by South Africa to the south and southeast, Namibia to the west and north, and Zimbabwe to the northeast. Its border with Zambia to the north near Kazungula is poorly defined but is, at most, a few hundred metres long.