The story that the elder nobleman told Miss Linda greatly resonated with the rest of the nobles in Caira.
He was a powerful, well connected man and had many dealings with the nearby nobles, letting many of the present nobles personally know the victims.
Hence when they heard recounteds of how the man's daughter in law was so cruelly murdered and how his grandson had been crippled and gone half mad from the trauma, it struck a personal cord with many of them.
Many also had their sons, daughters, or other close kin who suffered similarly.
And so now, they wanted revenge.
Sure, over the centuries they might have done similar things if not worse to the natives, but by now who was keeping count?
At that moment it was personal and the nobles would never accept the Margraves simply sitting inside their walls and wait out the disaster, walls that the nobles themselves paid for in the first place.