Challenge (Usually They're More Interesting Than This)

I was sitting at the Reference Desk, minding my own business, when I came across the following statement on the Chicken Spaghetti blog:

1. Grab the nearest book.
2. Open to page 123.
3. Find the fifth sentence.
4. Post the text of the next four sentences on your blog along with these instructions.
5. Don't you dare dig around for that "cool" or "intellectual" book on your shelves. (I know you were thinking about it.) Just pick up whatever is closest.

I did. Here's what I found:

"I would like to know the truth about all these rumours and I am Your devoted Uncle, Aesculpaius Cultellus. Six weeks later, Gladius Ensa, the nephew, a captain of the VII Gallic Infantry, answered as follows: My dear Uncle, I have received your letter and I have obeyed your instructions. Two weeks ago our brigade was sent to Jerusalem. There have been several revolutions during the last century and there is not much left of the old city."

Dull, eh? This is a good kidlit quiz question, by the way. Can you name the book? In a way, it's the first of its kind.