Christos Yannaras (born 1935 in Athens, Greece) has been proclaimed 'without doubt the most important living Greek Orthodox theologian' (Andrew Louth), 'contemporary Greece's greatest thinker' (Olivier Clement), 'one of the most significant Christian philosophers in Europe' (Rowan Williams). However, until recently the English-speaking scholar did not have first-hand access to the main bulk of his work: in spite of the relatively early English translation of his The Freedom of Morality (1984), most of his books appeared in English fairly recently - such as Person and Eros (2007), Orthodoxy and the West (2006), Relational Ontology (2011) or The Schism in Philosophy (2015). In this volume, chapters shall examine numerous aspects of Yannaras' contributions to Orthodox theology, philosophy and political thought, based on his relational ontology of the person, later popularised in the Anglophone sphere by John Zizioulas. From political theology to Heidegger and the philosophy of language, from Yannaras' critique of religion to the patristic grounding of the theology of the person and from Orthodoxy to the West, this volume comprises a panorama of Christos Yannaras' transdisciplinary contributions.