The passport is possibly the most important, and most universal document in the world. People live and die for them and by them, so it's a bit strange to think that they're such a rarely studied subject. This book does a good job from lots of angles, combining amusing anecdotes dredged from the most unlikely places, interesting reproductions of various curiosities, technology etc all woven into the not so straightforward history of the passport and it's significance.
This is not a hardcore history text, nor is it a flimsy "look at what I studied over the holidays" throwaway. It's well thought through (as it should be after multiple decades of experience), structured and entertaining. Perhaps the only thing missing is more current debate around the passports role in social control or freedom, but then I suppose this is not what the book was aiming to do, and would introduce more academic waffle than would be desirable in such a readable book.
I liked it, and I think you'll like it too.