A thousand years ago, the Wari empire stretched across Peru. At its height, it covered an area the size of the Eastern seaboard of the US from New York City to Jacksonville. It lasted for 500 years, from 600 to 1100 AD, before eventually giving rise to the Inca. That’s a long time for an empire to remain intact, and archaeologists are studying remnants of the Wari culture to see what kept it ticking. A new study found an important factor that might have helped: a steady supply of beer.