This monumental, two volume work brings together for the first time, in the original languages and in a fresh English translation, all the decrees of all the ecumenical councils from Nicaea I to Vatican II. As such it represents an indispensable reference work for theologians and historians, as well as for anyone interested in the development of Christian thought and doctrine. Indeed, these decrees represent the most authoritative distillation of Christian tradition and therefore stand alongside the Bible as one the twin pillars of Christian beliefs.