VACANCY

Why would a stranger let you sleep under their roof?

For four thousand years, someone has had to answer that question every night - and the answers built the world's inns, hotels and motels.

VACANCY is a global history of the room you sleep in when you are a long way from home. It runs from a Babylonian law code that ordered a tavern keeper to seize the outlaws drinking under her roof, to a platform where a numerical score decides whether a stranger in Lisbon will open her door to a stranger from Osaka.

Along the way:

• The Greek conviction that the beggar at the door might be a god - and why that belief was a functioning enforcement mechanism, not a superstition
• Roman roadside stations funded by seizing food, animals and beds from villages that got nothing in return
• The caravanserais of Anatolia, which fed any traveler and his animals free for three days, financed by patrons who had been dead for centuries
• A Japanese hot-spring inn that has taken guests since the year 705, and what "thirteen hundred years old" actually means
• Why every society that left a written opinion despised innkeepers - and why the contempt was rational
• An English rule, still law in half of Europe, that makes a hotel answerable for your suitcase whether or not anyone was careless
• How a Boston hotel in 1829 invented the private lockable room, and why that single door changed everything after it
• The engineering decision from 1908 that explains why your hotel bathroom is beside the door instead of the window
• The guidebook, compiled by postal workers, that Black American families needed in order to drive across their own country
• And why the legal basis for opening every American hotel to everyone turned out to be not citizenship, but travel

Most histories of hotels begin in nineteenth-century America. This one spends two-thirds of its length before that, and outside the West - in Mesopotamia, Anatolia, Persia, China, Japan, India, the Andes and the Mediterranean.

Underneath the buildings is a single problem that has never been solved, only re-answered: how do two people who have never met, and who will never meet again, arrive at enough trust for one of them to fall asleep in the other's house?

Thirty-four chapters. Six continents. Four thousand years. One question.