"Tsenov is famous in Italy for his logical Bulgarian erudition and in Germany, with his previous work, he has revolutionized the origin of the Bulgarians and the other Slavs in the Balkans ... The thesis on the Thracian-Bulgarian origin of the Bulgarians was supported by Tsenov with a great controversial liveliness, sometimes quite brave, always resting on arguments that can not be denied without an absolute competence, because the author who has devoted his entire life to this study does not allow concessions ... He establishes in a complete picture Irvine inhabit life, the language of the Thracians and Illyrians, ethnic influence they exercised on the development of peoples-conquerors in the Balkans, to reach aboriginal character of the Bulgarians, which is comprehensively addressed and clearly and accurately exposed. All this work has been examined with a critical chronological and convincing method. He deserves praise. Mr. Tsenov shows that he is a man who has a deep knowledge and a great skill, a man who has put all his love and his whole excitement, always inspired by a belief that undoubtedly gives him the right to delight."

“Tsenov comes out of a detailed source-check which many of his predecessors have hardly ever seen. It facilitates the reader by printing these sources in the original ... From the same sources it can be seen that the Bulgarians were south of the Danube for 350 years, so they did not come until 679. from the Volga, but not only before the Slavs, but before the Huns in Illyria and Thrace, that the Bulgarians lived in 350 AD. along the lower Danube in the Byzantine Empire, i. south of the lower Danube, and that they were a mighty people, not only in Moesia but also in Thrace and Illyria.”

“It is important that Tsenov's facts show that the Bulgarians have been in the Balkans since the 4th century, with which the author has even shaken the general opinion about the founding of the Bulgarian state in 679. by a handful of Mongol Bulgarians”

“Dr. Tsenov, who has been a lecturer at Berlin University for years, has a double merit. He again gives us a new composition on the oldest story of the Bulgarians, which, almost 50 years after the old history of Konstantin Irechek, occupies a prominent place. It brings the Bulgarians to the many difficult to reach Latin, Byzantine and Old Slavic sources. The origins of the Southeastern countries and church history are, in any case, set by Tsenov for us in Central Europe in a new light.”

“If historians who are able to check the facts admit their allegiance, we will have to change some of our beliefs about the origins of Germanism. We have to add that this book is abundant with documents and that some explanations - to say the Christianization of the Goths and the Huns - are very well documented and deserve serious attention”

“When I published my book "The Origins of the Bulgarians" in 1907, from which it came out that the Bulgarians were something better than what was being thought of for them, I was declared a patriot and, therefore, which is outside the law. Everyone who criticized me has criticized me not in content, not because the data I have stated is untrue, but because I was a patriot who reported facts that the Bulgarians were both valiant and cultural when, in the opinion of my opponents, it was obvious that the Bulgarians were created by nature as a fertilizer on foreign fields ... My chauvinism, proving that Thrace and Macedonia were old Bulgarian lands, threatened on the one hand Russia, which aspired to South Thrace as a hinterland of the Dardanelles and on the other hand - Pannonian Slavs who aspired to Thessaloniki. The opinion of Paninese Slavs was also supported by Bulgarian scientists.”

“In the time of his reign , the Thracian Vitalian kept under some pretense, saying, because of the exiled bishops, and took Thrace, Scythia and Moesia, to Varna and Anhialo, leading a large number of Huns and Bulgars”