The concept of the "self-emptying" or kenosis of Christ is taken from Paul's Letter to the Philippians, and it has presented an interpretive puzzle from the beginning of Christianity. This dissertation surveys the different interpretations of kenosis in Greek Christianity through the trinitarian and christological controversies of the fourth and fifth centuries. This development culminates in the writings of Cyril of Alexandria, for whom kenosis was a very prominent theological concept.In comparing this historical development with contemporary interpretations of Philippians 2:7, it becomes apparent that the ancient conversations were centered very much on questions of how to speak of who exactly is "emptying himself." This quickly comes to involve disputes concerning the understanding of who God is and how union with human nature is possible. Cyril emphasizes that it is the Word of God that is the subject of the emptying and who makes human nature his own to such a degree that one should not speak of the human and divine natures as having any independent voice or activity.The dissertation opens with a significant survey of twentieth century interpretation of Philippians 2:7, in order to provide points of comparison with antiquity. It is striking to find that many of the same problems and questions that arise for contemporary interpreters are similar to the ones with which ancient interpreters struggled.