The book explores the subject of Russian icons and their changes as well as the discussion on art that unfolded in Russia in the 15th and 16th centuries. Taking the representation of the Old Testament Trinity, attributed to Andrei Rublev, as its point of departure, it discusses and analyses the key issues of the iconography of the Holy Trinity and the process of the emergence and the dissemination of the imagery of God the Father and the New Testament Trinity in Russia. These issues are framed in the context of the debate that took place at the time within the Muscovite Orthodoxy, which concerned heresy, the relations with other denominations, the identity of the Russian Orthodox Church and the place of the icons in the existing canon.