text: Go a long way back into history to figure this one out - it's a knot.   Shooting thirteen civilians on one day was not a good move by the British ("bloody sunday"), but lots more happened than that.  Prior to the marches that ended with bloody sunday there was institutional sectarianism that the brits tolerated, including the built-in majority for protestants in government across the province.  For the true story you have to go back at least as far as Cromwell, and possibly as far as Robert the Bruce, and you have to be completely dispassionate as you read it.