http://www.sciencemag.org/news/2020/09/warrior-skeletons-reveal-bronze-age-europeans-couldn-t-drink-milk

Bones from a Bronze Age battlefield on the banks of the Tollense River in Germany.

About 3000 years ago, thousands of warriors fought on the banks of the Tollense river in northern Germany. They wielded weapons of wood, stone, and bronze to deadly effect: Over the past decade, archaeologists have unearthed the skeletal remains of hundreds of people buried in marshy soil. It’s one of the largest prehistoric conflicts ever discovered.