The earliest dated Iron Age site in Botswana is an iron smelting furnace in the Tswapong hills near Palapye, dated around 190 AD - probably associated with eastern Iron Age Bantu farming culture from the Limpopo valley. Meanwhile farming culture of the western Iron Age type spread through northern and into south-eastern Botswana. The remains of beehive-shaped small houses made of grass-matting, occupied by western Early Iron Age farmers, have been dated from about 420 AD around Molepolole, and a similar site in the western Transvaal near Pretoria has been dated as early as 300. There is also evidence of early farming settlement of a similar type in Botswana west of the Okavango delta, existing alongside Khoesan hunter and pastoralist sites in the Tsodilo hills, dated from around 550 AD. Archaeologists now have difficulty in interpreting the hundreds of rock paintings in the Tsodilo hills, which were once assumed to be painted by 'Bushman' hunters remote from all pastoralist and farmer contact.

Iron Age Chiefdoms and States
Eastern Botswana chiefdoms
From around 1095 south-eastern Botswana saw the rise of a new culture, characterized by a site on Moritsane hill near Gabane, whose pottery mixed the old western style with new Iron Age influences derived from the eastern Transvaal (Lydenburg culture). The Moritsane culture is historically associated with the Khalagari (Kgalagadi) chiefdoms, the westernmost dialect-group of Sotho (or Sotho-Tswana) speakers, whose prowess was in cattle raising and hunting rather than in farming.

In east-central Botswana, the area within 80 or 100 kilometres of Serowe (but west of the railway line) saw a thriving farming culture, dominated by rulers living on Toutswe hill, between about 600-700 and 1200-1300. The prosperity of the state was based on cattle herding, with large corrals in the capital town and in scores of smaller hill-top villages. (Ancient cattleandsheep/goatcorrals are today revealed by characteristic grassgrowing on them.) The Toutswe people were also hunting westwards into the Kalahari and trading eastwards with the Limpopo. East coast shells, used as trade currency, were already being traded as far west as Tsodilo by 700.

The Toutswe state appears to have been conquered by its Mapungubwe state neighbour, centred on a hill at the Limpopo-Shashe confluence, between 1200 and 1300. Mapungubwe had been developing since about 1050 because of its control of the early gold trade coming down the Shashe, which was passed on for sale to sea traders on the Indian Ocean. The site of Toutswe town was abandoned, but the new rulers kept other settlements going - notably Bosutswe, a hill-top town in the west, which supplied the state with hunting products, caught by Khoean hunters, and with Khoesan cattle given in trade or tribute from the Boteti River. But Mapungubwe's triumph was short-lived, as it was superceded by the new state of Great Zimbabwe, north of the Limpopo River, which flourished in control of the gold trade from the 13th to the 15th centuries. It is not known how far west the power of Great Zimbabwe extended. Certainly its successor state, the Butua state based at Kame near Bulawayo in western Zimbabwe from about 1450 onwards, controlled trade in salt and hunting dogs from the eastern Makgadikgadi pans, around which it built stone- walled command posts.

The Butua state passed from the control of Chibundule (Torwa) rulers to Rozvi invaders from the north-east in about 1685. Under Rozvi rule, the common people of Butua became known as the Kalanga. The old Chibundule rulers appear to have fled to the western Kalanga (in the area now in Botswana), where they became known as Wumbe, giving rise to a number of local Kalanga chiefdoms. Other Kalanga chiefdoms descended from Mengwe, the 'uncle' of Chibundule, or from groups of Sotho attracted from the south such as the Nswazwi and Chizwina (Sebina) chiefdoms.

The main Tswana (Central Sotho) dynasties of the Hurutshe, Kwena and Kgatla were derived from the Phofu dynasty, which broke up in its western Transvaal home in the 1500-1600 period. Oral traditions usually explain these migrations as responses to drought, with junior brothers breaking away to become independent chiefs. The archeology of the Transvaal shows that the farming population was expanding and spreading in small homesteads, each clustered round its cattle corral, across open countryside - with a few larger settlements as evidence of petty chiefdoms. But after about 1700 the settlement pattern changed, with stone-walled villages and some large towns developing on hills - evidence of the growth of states often hostile to each other. These states were probably competing for cattle wealth and subject populations, for control of hunting and mineral tribute, and for control of trade with the east coast.

The Kololo moved through Shoshong, expelling the Ngwato northwards, to the Boteti River, where they settled for a number of years - attacking the Tawana and raiding for cattle as far west as Namibia, where they were warded off in a battle with Herero. In about 1835 they settled on the Chobe River, from which the Kololo state stretched northwards until its final defeat by its Lozi subjects on the upper Zambezi in 1864. Meanwhile the Kololo were followed in their tracks by the Ndebele, a raiding army led by Mzilikazi, who settled in the Butua area of western Zimbabwe in 1838-40 after the conquest of the Rozvi. These wars are called the Difaqane by historians.

The most remarkable Tswana king of this period was Sechele (ruled 1829-92) of the Kwena around Molepolole. He allied himself with British traders and missionaries, and was baptized by David Livingstone. He also fought with the Boers, who tried to seize Africans who fled to join Sechele's state from the Transvaal. But by the later 1870's the Kwena had lost control of trade to the Ngwato, under Khama III (ruled 1875-1923), whose power extended to the frontiers of the Tawana in the north-west, the Lozi in the north and the Ndebele in the north-east.

The British government continued to regard the protectorate as a temporary expedient, until it could be handed over to Rhodesia or, after 1910, to the new Union of South Africa. Hence the administrative capital remained at Mafeking (Mafikeng), actually outside the protectorate's borders in South Africa, from 1895 until 1964. Investment and administrative development within the territory were kept to a minimum. It declined into a mere appendage of South Africa, for which it provided migrant labour and the rail transit route to Rhodesia. Short-lived attempts to reform administration and to initiate mining and agricultural development in the 1930s were hotly disputed by leading Tswana chiefs, on the grounds that they would only enhance colonial control and white settlement. The territory remained divided into eight largely self-administering 'tribal' reserves, five white settler farm blocks, and the remainder classified as crown (i.e. state) lands.

The extent of Bechuanaland Protectorate's subordination to the interests of South Africa was revealed in 1950. In a case that caused political controversy in Britain and the Empire, the British government barred Seretse Khama from the chieftainship of the Ngwato and exiled him for six years. This, as secret documents have since confirmed, was in order to satisfy the South African government which objected to Seretse Khama's marriage to a white woman at a time when racial segregation was being reinforced in South Africa under apartheid.

After long resistance to constitutional advance before economic development could pay for it, the British began to push political change in 1964. A new administrative capital was rapidly built at Gaborone. Bechuanaland became self- governing in 1965, under an elected BDP government under Seretse Khama as prime minister. In 1966 the country became the Republic of Botswana, with Seretse Khama as its first president.

For its first five years of political independence, Botswana remained financially dependent on Britain to cover the full cost of administration and development. The planning and execution of economic development took off in 1967-71 after the discovery of diamonds at Orapa. The essential precondition of this was renegotiation of the customs union with South Africa, so that state revenue would benefit from rising capital imports and mineral exports - rather than remaining a fixed percentage of total customs union income. This renegotiation was achieved in 1969.

South Africa was obliged to step down from its objections to Botswana building a road, with US aid finance, direct to Zambia avoiding the old railway and road route through Rhodesia. From 1974 Botswana was, together with Zambia and Tanzania, and joined by Mozambique and Angola, one of the "Front Line States" seeking to bring majority rule to Zimbabwe, Namibia and South Africa.

The later 1970s saw civil war in Rhodesia, and urban insurrection in South Africa, from which refugees flowed into Botswana. When Botswana began to form its own army, the Botswana Defence Force, the Rhodesian army crossed the border and massacred 15 Botswana soldiers in a surprise attack at Leshoma (February 1978). Botswana played its part in the final settlement of the Rhodesian war, resulting in Zimbabwe independence in 1980. But its main contribution was in formulating the Southern African Development Coordination Conference, to look to the future of the region.

The idea behind SADCC, as expounded by Seretse Khama, was to coordinate disparate economies rather than to create a unified market in southern Africa. All the states of southern Africa, except South Africa (and Namibia), formed SADCC in 1980, to work together in developing identified sectors of their economies - particularly the transport network to the ports of Mozambique.

Between 1984 and 1990 Botswana suffered from upheavals in South Africa when South African troops raided the 'Front Line States'. Two raids on Gaborone by the South African army in 1985 and 1986 killed 15 civilians. A new era in regional relations began with the independence of Namibia in 1990, and continued with internal changes in South Africa culminating in its free elections of 1994.

The economy continued to expand rapidly after a temporary slump in diamond and beef exports at the beginning of the 1980s. The expansion of mining output slowed in the 1990s, but was compensated for by the growth of manufacturing industry producing vehicles and foodstuffs for the South African market.

Botswana handed over leadership of SADCC, now the Southern African Development Community(SADC), to South Africa in 1994. But the secretariat of SADC remains housed in the capital of Botswana, Gaborone.