The Orthodox Church has actively participated in the promotion of Christian unity since the early twentieth century and has contributed to its progress. The Council of Crete, held in 2016, reiterated Orthodoxy’s commitment to advance Christian unity in accordance with its history, theology, and tradition. The Council delineated the theological and practical aspects of inter-Christian cooperation. However, there are persistent tensions in the relations among the Orthodox Churches that negatively impact the advancement of Christian unity, tensions that do not derive from doctrinal differences with other Christian traditions but stem from non-theological factors related mainly to the connection between church and nation and the rise of national self-governed (autocephalous) churches. Whereas the autocephalic system has roots in Orthodox ecclesiology and law, its contemporary practice has led to conflicting agendas and attitudes towards the West. To address this problem, this chapter proposes that a shift in mindset along with a serious reconsideration of the ecclesiology of autocephaly is essential. This entails implementing the autocephalic system with primatial institutions that should be exercised in a synodical way, thus safeguarding the unity of the Church.