St. Cyril of Alexandria, world famous theologian of the Universal Christian Church (†444). His works have enormous influence on the theological thought of all traditional churches. Nearly everything that Cyril has written, was known to scholars. Among exceptions was the Commentary on the Letter to the Hebrews, which was known only in small excepts, and the whole work was considered to be lost. However, recently, the Armenian translation of the first three chapters of that book was found in Armenian in Matenadaran, the Armenian depository of ancient manuscripts in Yerevan. Comparative data indicate that most probably, this work was unfinished by Cyril, and these three chapters are everything that Cyril has written in this commentary. In this book the original Armenian text is published for the first time.