As one who is an avid reader of Church history, I can say that this is the best volume of early Church history I have read. Henry Chadwick's account of the rise of Christianity, from its roots in Judaism to its decisive break from the mother religion, is weighty, concise and clear.
He explains how the early Christians saw themselves as Jews but that the decisive break came when they (the Christians) accepted Gentiles into the new movement. Thereafter, Chadwick explores the spread of Christianity in the Near East and eventually how it made its way to Rome. This is pretty standard stuff so far.
What I liked about the book was the explanation of the different Christological positions in the controversies surrounding the question of Christ's nature. It is in Chadwick's book that I understood Arius and Arianism, Nicene confessions, Chalcedonian Christianity, Monophysitism and Nestorianism. These controversies, which seem drab and overly punctilious to modern readers, were, as Chadwick points out, one of the reasons for the eventual split of the Church into Latin and Orthodox Christianities.
The book is not just a boring academic tome. He enlivens the book with lively descriptions of the Church Fathers; Ambrose, Tertullian and the key characters (and politics) in the Christological consipiracies. If you are interested in understanding the rise of Christianity in the Ancient World and want a readable account of the abstruse, high-falutin Christological terms that have come to define Christian doctrine then this book is a must-read. It deserves my 5 stars.