This book weighs in at over 1,000 pages - 22 books in the original. Fortunately for the reader, St. Augustine frequently wanders from his main theme, for many pages at a time, providing fascinating explorations of why the number 11 symbolises sin (short answer: it transgresses the perfect 10 of the Decalogue); of how the Ark of Noah is an allegory of Christ; of the creation and fall of the angels, and of much, much more.

These questions are digressions, but they do help to make the book palatable to the modern reader. Perhaps the best way to read is to plunge into the book a few hundred pages in; beginning at the beginning is like beginning the Bible at Genesis 1: one is likely to get bogged down part way through. St. Augustine wrote the book during the years 413-426: if he could take 13 years writing his baggy but entertaining monster, the reader can hardly be expected to digest it in a single gulp.

The "City of God" should on no account be confused with the "Mystical City of God", an even more voluminous work by a 17th-century Spanish nun named Maria of Agreda.