As a ruler of the church of Alexander and president of the Third Ecumenical Council of 431, Cyril was one of the most powerful men of the fifth century. Not only did he define the concept of christological orthodoxy for the next two centuries, but he is also often regarded as an unscrupulous cleric who was responsible for the murder of the female philosopher Hypatia and for the overthrow of the archbishop Nestorius. Cyril of Alexandria presents key selections of Cyril's writings in order to make his thought accessible to students. The writings are all freshly translated and an extended introduction outlines Cyril's life and times, his scholastic method, his christology, his ecclesiology, his eucharistic doctrine, his spirituality, and his influence on the Christian tradition.