This history of the development of the rites of Christian initiation is quite thorough (though not exhaustive), sifting through documentary evidence from both the East and the West in the pre-Nicaean period, the fourth and fifth centuries, the Middle Ages, the Protestant and Catholic reformations of the sixteenth century, and today. It could be a bit dry and academic for the casual reader, but it’s an indispensable reference for anyone interested in liturgical history. It’s also proving to be quite a substantive resource for a paper I’m writing on the place of mystagogy in the initiation process.