In 2018/19, the Ecumenical Patriarch of Constantinople initiated the establishment of an autocephalous (independent) Orthodox Church in Ukraine. This process was met with harsh criticism by the Russian Orthodox Church and eventually led to a split in the entire Orthodox world. The contributions to this volume examine this conflict and discuss the underlying causes for it in a broader perspective. They deal with several aspects of Orthodox theology, history, church life and culture, and show the existence of a serious rift in the broader Orthodox world. This became visible most recently in the conflict over the Ukrainian Church autocephaly, yet it has a longer, and more complex historical background.