The Boer were Dutch settlers in South Africa who weren't too pleased to have the Rule of the British Empire thrust upon them. 'Boer' is from the Dutch for 'farmer' and they were good soldiers being brave and exellent shots. This wasn't enough however and they fought and lost two wars against the British due to their lack of dicipline and lack of formal leadership. They were very hard to kill as well, as their sloping foreheads acted like the glacis on a tank.
The Quintessential boer is 'Van der Merwe' in the same way as the quintessential Irishman is Pat O'Reilly. Many is the joke about Van der Merwe.
Van der Merwe was out chopping wood on his farm. A lightning bolt flashes from the sky striking the axe head and knocking him spinning into the well. The now red hot axe head is flung into the barn where it sets the hay on fire. The livestock in the barn perishes to the last beast. A gust of wind catches some sparks and sets fire to the farmhouse. In fleeing the burning building, Van der Merwe's wife falls and breaks her leg. When he pulls himself from the well Van der Merwe surveys the scene of devastation, weakly lifts his fist to heaven and screams "DAMN THOSE BLACKS!"
See also: Boer War.