The Khmer Empire

In the 13th century, when London held about 20,000 people, the Khmer Empire’s capital city of Angkor housed between 700,000 and a million residents. It was the largest pre-industrial city on earth, sprawling across more square miles than modern New York City’s five boroughs combined. Yet almost everything we know about how this empire began comes from a single stone inscription written 200 years after the fact. The rest of its history is told not on papyrus or parchment—which rotted in the monsoon climate—but on the walls of its own temples.

The God-King Gambit

The Khmer Empire, centered in modern-day Cambodia, lasted from 802 to 1431 CE. It emerged from a loose collection of principalities called Chenla, which had been fractured by invasions from the Javanese Shailendra dynasty. The key figure was Jayavarman II, a noble taken as a political prisoner to Java who later returned and began conquering territory up the Mekong River. His masterstroke was not military but religious: he traveled to Mount Mahendraparvata with a Hindu Brahmin and performed a sacred ceremony that made him a devaraja—a God-King. As the hosts put it, "he was the first guy that really thought of this." By claiming divine status, he united the fractious principalities under a single authority that could command absolute obedience. The capital was established at Hariharalaya, chosen for its proximity t