Prior to British conquest and incorporation of their territory, called "Tembuland" in the 19th century, the Thembu had an independent kingdom. The clan name or isibongo of the Thembu kings is Madiba. Recent kings have used the surname of Dalindyebo, from the name of a 19th century king.
After conquest, the Thembu were administered by the government of the Cape Colony as one of the Transkeian Territories, which with the exception of a few missionaries and white traders, were treated as lands reserved for African occupation. Other peoples in the territories who had formerly had independent kingdoms included the Gcaleka branch of the Xhosa, the Mpondo (who split into two kingdoms late in the 19th century), the Bhaca and the Xesibe. Under apartheid the Transkei was turned into a bantustan. In the ethnic theory underpinning apartheid, the Transkei was regarded as the "homeland" of the Xhosa people. As a result, the Thembu people are often misidentified as being Xhosa.
The most internationally famous Thembu person is Nelson Mandela, whose father was a high status royal councillor from a junior branch of the Madiba clan.