Bergen, Doris L. The Sword of the Lord: Military Chaplains from the First to the
Twenty-First Century. Notre Dame: University, 2004.
This is a great read for a new candidate or somone interested in the history of the chaplaincy. It is throughly academic and is therefore appealing to the seminarian or scholar. Bergen focuses her attention on the Western development of the chaplain from the Roman Empire to today. It's a great read, I highly recommend it if you are interested in the history of the chaplaincy.