Preface In 1984, while preparing for the exam in medieval Bulgarian history, I came across Peter Juhas's book "Turko-Bulgars and Hungarians". He discussed the connection between the Seklery Rovas and the writing of the Asparuh Bulgars in one of the chapters of his book. The author had offered a long list of inscriptions attributed to the Bulgars, among which stood out about 60 inscriptions found in rock churches near the village of Murfatlar, once part of the First Bulgarian Kingdom. This fact was an incredible surprise to me - very little was known about the language of the Danube Bulgars: a few words, military titles and names. Two Bulgar inscriptions in scientific circulation were written in Greek letters, and scholars suggested that they might be an inventory of weapons. I couldn't believe that somewhere existed 60 inscriptions written in the mysterious language of the Bulgars and no one talks about it. Later V. Beshevliev's article about...