It is estimated that hominids lived in Botswana during the Pleistocene.[17] Stone tools and animal remains indicate that all areas of the country were inhabited at least 400,000 years ago.[18] It was claimed to have been the birthplace of all modern humans from around 200,000 years ago.[19][20][21] Evidence left by modern humans, such as cave paintings, is about 73,000 years old.[22] The earliest known inhabitants of southern Africa are thought to have been the forebears of present-day San ("Bushmen") and Khoi peoples. Both groups speak click languages from the small Khoe-Kwadi, Kx'a and Tuu language families whose members hunted, gathered and traded over long distances. When cattle were first introduced into southern Africa about 2,000 years ago, pastoralism became a major feature of the economy since the region had large grasslands free of tsetse flies.[23] .mw-parser-output .tmulti .multiimageinner{display:flex;flex-direction:column}.mw-parser-output .tmulti .trow{display:flex;flex-direction:row;clear:left;flex-wrap:wrap;width:100%;box-sizing:border-box}.mw-parser-output .tmulti .tsingle{margin:1px;float:left}.mw-parser-output .tmulti .theader{clear:both;font-weight:bold;text-align:center;align-self:center;background-color:transparent;width:100%}.mw-parser-output .tmulti .thumbcaption{background-color:transparent}.mw-parser-output .tmulti .text-align-left{text-align:left}.mw-parser-output .tmulti .text-align-right{text-align:right}.mw-parser-output .tmulti .text-align-center{text-align:center}@media all and (max-width:720px){.mw-parser-output .tmulti .thumbinner{width:100%!important;box-sizing:border-box;max-width:none!important;align-items:center}.mw-parser-output .tmulti .trow{justify-content:center}.mw-parser-output .tmulti .tsingle{float:none!important;max-width:100%!important;box-sizing:border-box;text-align:center}.mw-parser-output .tmulti .tsingle .thumbcaption{text-align:left}.mw-parser-output .tmulti .trow>.thumbcaption{text-align:center}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .tmulti .multiimageinner span:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent) img{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .tmulti .multiimageinner span:not(.skin-invert-image):not(.skin-invert):not(.bg-transparent) img{background-color:white}}Domboshaba Ruins Stone Wall (top) and clay pottery plate (bottom) It is unclear when Bantu-speaking peoples first moved into the country from the north, although AD 600 seems to be a consensus estimate. In that era, the ancestors of the modern-day Kalanga moved into what is now the north-eastern area of the country. These proto-Kalanga were closely connected to states in Zimbabwe as well as to the Mapungubwe state. One notable remnant of this period is Domboshaba ruins, a cultural and heritage site in Botswana initially occupied towards the end of the Great Zimbabwe period (1250–1450), with stone walls that have an average height of 1.8 metres. The site is a respected place for the people living in the region, and it is believed that the chief lived on the top of the hill with his helpers or assistants. These states, located outside of current Botswana's borders, appear to have kept massive herds of cattle—apparently at numbers approaching modern cattle density—in what is now the Central District.[24] This massive cattle-raising complex prospered until around 1300 and seems to have regressed following the collapse of Mapungubwe. During this era, the first Tswana-speaking groups, the Bakgalagadi, moved into the southern areas of the Kalahari. These various peoples were connected to trade routes that ran via the Limpopo River to the Indian Ocean. Trade goods from Asia such as beads made their way to Botswana, most likely in exchange for ivory, gold and rhinoceros horn.[25] The Toutswemogala Hill Iron Age settlement's radio-carbon dates range from the 7th to the late 19th century, indicating it was occupied for more than 1,000 years.[26] The hill was part of the formation of early states in southern Africa, with cattle as a major source of economy.[26] The Toutswe settlement includes house-floors, large heaps of vitrified cow dung, and burials while the outstanding structure is the stone wall.[27] Around 1000 AD, the Toutswe people moved into Botswana.[28] However, agriculture also played a vital role in the longevity of Toutswemogala Hill's extended occupation, as many grain storage structures have also been found on the site. Many different stratified layers of housing floors further signalled continuous occupation over hundreds of years. The arrival of the Tswana speakers' ancestors who came to control the region has yet to be dated precisely. Members of the Bakwena, a chieftaincy under a leader named Kgabo II, made their way into the southern Kalahari by AD 1500 at the latest, and his people drove the Bakgalagadi inhabitants west into the desert. Over the years, several offshoots of the Bakwena moved into adjoining territories. The Bangwaketse occupied areas to the west, while the Bangwato moved northeast into former Kalanga areas.[29] Not long afterwards, a Bangwato offshoot known as the Batawana migrated into the Okavango Delta, probably in the 1790s.[30] Mfecane and Batswana-Boer Wars[edit] Main article: Mfecane 1905 German map of Southern Africa, showing the still-undivided Bechuanaland area The first written records relating to modern-day Botswana appear in 1824. These records show that the Bangwaketse had become the predominant power in the region. Under the rule of Makaba II, the Bangwaketse kept vast herds of cattle in well-protected desert areas, and used their military prowess to raid their neighbours.[31] By this time, other chiefdoms in the area had capitals of 10,000 or so and were fairly prosperous.[32] This equilibrium came to end during the Mfecane period (1823–1843) when a succession of invading peoples from South Africa entered the country. Although the Bangwaketse were able to defeat the invading Bakololo in 1826, over time all the major chiefdoms in Botswana were attacked, weakened and impoverished. The Bakololo and AmaNdebele raided repeatedly and took large numbers of cattle, women and children from the Batswana – most of whom were driven into the desert or sanctuary areas such as hilltops and caves. Only after 1843, when the Amandebele moved into western Zimbabwe, did this threat subside.[33] Sechele I, who led a Batswana Merafe Coalition against Boers in 1852 During the 1840s and 1850s, trade with Cape Colony-based merchants opened up and enabled the Batswana chiefdoms to rebuild. The Bakwena, Bangwaketse, Bangwato and Batawana cooperated to control the lucrative ivory trade and used the proceeds to import horses and guns, which in turn enabled them to establish control over what is now Botswana. This process was largely complete by 1880, and the Batswana thus subjugated the Bushmen, Kalanga, Bakgalagadi and other current minorities.[34] Following the Great Trek, Afrikaners from the Cape Colony established themselves on the borders of Botswana in the Transvaal. In 1852, a coalition of Tswana chiefdoms led by Sechele I defeated Afrikaner incursions at the Battle of Dimawe and, after about eight years of intermittent tensions and hostilities, eventually came to a peace agreement in Potchefstroom in 1860. From that point on, the modern-day border between South Africa and Botswana was agreed on, and the Afrikaners and Batswana traded and worked together comparatively peacefully.[35][36] In 1884, Batawana, a northern-based Tswana clan's cavalry under the command of Kgosi Moremi, fought and defeated the Ndebele's invasion of northern Botswana at the Battle of Khutiyabasadi. This was the start of the collapse of the Ndebele Kingdom in Zimbabwe, and it helped the Tswana speaking authority.[37] Due to newly peaceful conditions, trade thrived between 1860 and 1880. Christian missionaries were able to take advantage of this. The Lutherans and the London Missionary Society both became established in the country by 1856. By 1880, every major village had a resident missionary, and their influence slowly grew. Khama III, who reigned from 1875 to 1923, was the first of the Tswana chiefs to make Christianity a state religion, and a great deal of Tswana customary law changed as a result. Christianity became the de facto official religion in all the chiefdoms by World War I.[38] Colonialism[edit]