Cape Colony until 1910 ...
BTW - wasn't it the the abolition of slavery which made the cup runneth over and push the Freedom Loving Boers to took to the steppes and flee British Tyranny?
Abolition and complete emancipation, with compensation for the Dutch farm owners only if they went to London to claim it. That was what we were taught in school back in the day.
But a Boer is technically a cattle-farmer, not a crop-grower. The trek-boers were nomadic herders, basically. I don't think they had slaves like the people with fixed farms did.
But they didn't like having any government people bossing them around or wanting to collect taxes from them.