Defining a state as an empire requires many econimic, political and cultural indicators. It is not accidental that empires perished not so much as a result of enemy attacks, but rather when they had totally exhausted their potencial. However, in spite of all reservations, these periods are salient emanations of a nation. Notwithstanding the lower self-confidence of Bulgarians in the recent years, they need to know the glorious history of their medieval empire - and this book is devoted precisely to it.