The Trekboers were descendents of Dutch settlers, French Huguenot refugees, German Protestants, Friesians and smaller numbers of Belgians, Scandinavians, Scots, also some Indian slaves due to intermarriage, and an a mixture of Khoi and Malay due to absorption into the nascent Boer nation. The Trekboers began migrating from the areas near Cape Town, Paarl, and Stellenbosch during the 1690s and into the expanding eastern Cape frontier throughout the 1700s.

The Trekboers were semi-nomadic farmers also simply known as Boers (which is Dutch for "farmer") and spoke a language called Eastern Border Afrikaans. This language started out as a modified Dutch dialect but became a distinct language over time with a number of words having non Dutch origins, mainly words taken from French, German, Malay, Khoi, and later English origin.

Some Trekboers resisted Dutch rule and set up independent republics in the towns of Swellendam & Graaff-Reinet in 1795. This was later reversed by the British upon their acquisition of the Cape as a result of the Napoleonic Wars. Some Trekboers resisted British legislation in 1815 which led to a rebellion at Slagters Nek in which the British executed some of the Boer leaders of the rebellion. After experiencing further British encroachments and constant border wars with the Xhosa to the east as well as growing land shortages, a large number of Trekboers become Voortrekkers.

Some Trekboers crossed the Orange River at least a decade before the Voortrekkers did. In 1815 a Trekboer named Coenraad Du Buys (surname of French Huguenot origin) fled from the British & became the first White inhabitant of the (western) Transvaal, where he set up a farm.

During the nineteenth century both Trekboers (Afrikaans speaking migrants from the 1600s & 1700s who trekked into the eastern frontiers) and Voortrekkers (Afrikaans speaking pioneers who trekked into the interior during the 1830s & 1840s) were simply called Boers.

During the Twentieth century both Boers and the Cape Dutch--those who did not trek eastward & remained in the Western Cape--would become known as Afrikaners. A term that was applied to all White Afrikaans speakers.

While the term Trekboer has now become obsolete: there is still a cultural, linguistic (accents & some terms), and geographic difference between the Boers of Voortrekker, Trekboer, and Republican descent to those who are of Cape Dutch (as they were called mainly by trekking Boers) or Western Cape descent.