William Dool Killen's fascinating history of the Christian church explains how Christianity organised, grew and established its traditions during the first four centuries of its existence.

Profoundly detailed and well-researched, this book delves into ancient manuscripts, surviving historical records, and the Biblical canon to deliver an informed history. Killen sets out to map the progress of the ancient Christian church from its earliest establishment to the formal founding of Catholicism.

Killen published his history in 1859; this was prior to large scale archaeological excavations in Rome and Asia Minor, with texts such as the Didache at the time uncovered. Some obscure papers had been unearthed, their translation and reproductions were undistributed - thus even for Killen, a concerted scholar fluent in Latin and Greek, their investigation and use was difficult if not impossible.

Putting aside the shortcomings of his era, William Dool Killen's manual of church history is remarkable for its thoroughness, and as a marker for Biblical scholarship in the mid-19th century. We begin with a lengthy exposition of the Biblical New Testament, wherein the entire story of Jesus Christ is retold and discussed in Killen's own words.

Killen discourages readers looking for a purist interpretation of Christian practice in the early canon of the Apostles: he notes the history of the period, and how illiteracy and a sparser access to the religious texts. Thus, Killen argues, Christians are better placed to create a religion pure in its doctrine and tenets in the modern day, simply as they are better informed.

We hear how the church implemented procedure as it grew; elections for presidents, and appointments of bishops to better manage the growing base of adherents. Schisms in belief between the early church would rupture due to disagreement over festivals and aspects of observance.

Later in the book we observe the events through which the Bishop of Rome became distinguished by his authority. Rome would arise as the seat of the church, with the decisive actions of Bishop Victor on excommunication noteworthy. Formally Victor's authority extended barely fifteen miles from the gates of Rome; yet it is likely his decrees gained influence through negotiated unity with bishops and pastors farther afield.

Killen also devotes chapters to the establishment of various traditions, such as Eucharist and the Baptism. One profound conclusion arrives when he identifies baptism as a event involving the entire family; thus, the iconic practice of infant and children being baptized likely occurred from the earliest years of the church.

Further detail is given regarding aesthetic traditions in the church, with decorative items such as paintings prohibited in establishments as late as the 4th century AD. The evolution of a church's physical interior in terms of furnishings and appearance, increasingly molded via the centralized policy of the bishops, is much investigated.

On some occasions, Killen criticizes his sources while making use of them; in the case of Eusebius, his criticisms are levied toward the poverty of detail present in some of the historian's accounts. Acknowledging that history as a vocation was in its infancy, Killen nevertheless identifies the limitations of his sources.

The Ancient Church - Its History, Doctrine, Worship, and Constitution is thus a valuable manual. Whether you are a scholar or student of Christianity, an adherent, or a historian interested in the era described, Killen's lengthy treatise is worthy of examination, despite having itself become something of a lost gem over the years.