In 1453, Orthodox Christianity experienced not only the fall of Constantinople, but the beginning of the hibernation of a once-vibrant intellectual tradition: for nearly 400 years, most of the Orthodox world would suffer under Ottoman oppression. In the nineteenth century, the Orthodox Christian intellectual tradition would awaken from its slumber when Russian thinkers would begin responding to the flood of modern ideas and philosophies being imported from the West as a result of the reforms of Tsar Peter the Great. What is remarkable about this theological awakening is its consistency with the Byzantine intellectual tradition silenced by the Ottomans, most especially on the principle of divine–human communion as the core of Orthodox thought. Contemporary Orthodox theologians of the nineteenth and twentieth centuries would share a consensus that divine–human communion constitutes the very heart of Orthodox theology – it is where all theology thinking must begin and end. In addition to this consensus, the doctrine of the Trinity was considered, again in continuity with the Byzantine intellectual tradition, indispensable for conceptualizing the God–world relation in terms of divine–human communion. These points of agreement, however, did not preclude the development of three distinctive and, in part, mutually incompatible trajectories in contemporary Orthodox trinitarian theology. In this chapter, I will offer an analysis of the three most influential: the sophiology of Sergius Bulgakov, the apophaticism of Vladimir Lossky, and the communion ontology of John Zizioulas.