To the issue on confessional features of the development of canon law of the Christian church in the middle ages

The article is a review of A. Yu. Mitrofanov’s monograph dedicated to the development of canon law in the 11th - 12th centuries by representatives of the Catholic, Orthodox and Armenian Apostolic Churches. On the example of the biography, scientific heritage and evidence of Anselm’s work were considered questions of the struggle of the emperors of the Holy Roman Empire with the popes on the issue of investiture, reception of Greco-Roman law, systematization of canon law, organization of crusades. The role of Anselm Lukksky in the formation of the institution of papal legates is shown. Comprehension of the secular power by the Byzantine canonical consciousness is revealed on the example of the works of Theodore Valsamon, who wrote comments on the Nomocanon of Photius, and the canonical position of the Armenian Apostolic Church towards Greeks - based on Nerses Lampronsky’s answers. The article highlighted the controversial issues - necessity to consider the systematization of canon law in the context of the Roman law reception, the impact of Feodor Valsamon’s comments to the Nomacanon of Photius on the development of canon law in Russia, the tradition of using the term «militant» in relation to the Church and others