The book "The Beginning of the Greco-Bulgarian Dissension and the Revival of the Bulgarian Nationality" was written by Professor Nikolai Ivanovich Petrov and published in Kiev in 1886 by G. T. Korchak-Novitskogo printing house. The publication consists of 105 pages and has a format of 23 cm. In his work, Petrov analyzes the Greco-Bulgarian conflict, which escalated after the Eastern War of 1853-1855. Initially, the strife was expressed in the desire of the Bulgarians to free themselves from hierarchical subordination to the Greeks, while the latter sought to maintain their power over the Bulgarian clergy. Although the conflict initially had a church character, over time it acquired political significance, reflecting the desire of the Bulgarian people for national revival and self-determination. This publication is of interest to historians, researchers of the Balkan region and all those who are interested in the history of the Bulgarian national movement and church relations in the Balkans in the XIX century.