Explain the cause of the field between the families of Ulrich von Gladwitz and Georg Znaeym

The feud started three generations before the story began. The feud started with a dispute over land ownership. Ulrich's grandfather, in a "famous law suit," won back the land illegally possessed by Georg's ancestors. Georg's family did not accept the court judgment and retaliated with "a long series of poaching affrays and similar scandals." There has been "bad blood" between the two families ever since then.