I have been following up my family, trying to trace out all the various family lines back to when they came to South Africa. My grandmother started this process, poring through baptismal records and death notices and such.
She did this during the height of Apartheid, so every time she found a non-white ancestor, she summarily stopped or fudged a good European one. So now I have a good framework, but I have to check her work and correct and extend it.
The first generations of Europeans that came to South Africa married their freedwomen or the daughters of slaves. Phenotypically I look white, but I have Bengali, other Indian, Malay, Timorese, Angolan, Malagasy, Khoisan and even one Chinese ancestor in addition to my Dutch, German, French, English, Scottish, Italian, Portuguese and Danish ones. It can be quite strange, although the vast majority of my ancestry lies with the French, Germans and Dutch.
I found an ancestor called Maria Kickers who had four sons. Her husband then claimed they were all another man's and a big divorce case followed. Eventually she admitted they were another other man, Friedrich Botha's children, but people in the case testified she had other affairs.
With modern genetic evidence, one of the four Botha boys turns out to be another man's child - Ferdinand Appel. For 300 years a quarter of the Bothas weren't really Botha. I am descended from fake and true Bothas myself.