This great civilization has sunk into the abyss of time. Her proud story turned into a legend, a fairy tale, a failure. Her brilliant culture is consigned to oblivion. The names of her illustrious cities - Arkona, Retra, Vineta - are now known less than the villages of some Inca or Aztec. Speaking of fallen civilizations, we usually imagine ruins braided by vines in distant jungles or ruins at the bottom of the ocean, we remember legendary names: Atlantis, Lemuria, My. But, it turns out, not in the antediluvian eras, but less than a thousand years ago, and not on other continents, but very close to the great civilization of our ancestors, competing on equal terms with the Holy Roman Empire and the powerful Byzantium - and now actually forgotten.