Probalby it is imposible to detect the place, where the solid, giant castle called Nordburg was built. Only old legends tell stories about an original castle’s structure, that was able to resist the treats of conquests, and about the amazing builders, who were able to build the wonderful castle with its amazing halls, towers and gardens. In the era of the biggest Nordburg’s fame, the Blue cross was born out. As the Nordburg castle was owned by nobility usually, there was the royal crown on the coat of arm of the knights, who were called Seversti pani. Just a few gravures show, how the flag and the shield of that knights looked like. According to some latin cronicles, the cross was blue and the flag was halving- blue and white. There was the blue and white royal crown on the middle of the cross, and a small blue cross on the white part of the big cross, as you can see on the picture. In those cronicles, we can find a gravure of blue and white knihgt with a horse, a flag and a shield, as well. Nobody knows, what happened with the castle, the knights and the kings. Only legends, which are written in ancient cronicles, tell stories about wisdom of the old scholars, braveness of the knights and cleverness of beautiful women. As the castle Nordburg disappeared, the actual association Spolecenstvi severskych panu resides at the Helfstyn castle. According to the slogan, which was writtenon the gravure of a knihgt with a horse- „UBI EST CONCORDIA, IBI EST VICTORIA“ (where the unity exists, there the victory exists), we are trying to keep medieval traditions, culture and knowledges and bring them to people, who love history