Ancient people in China systematically mined and burned coal up to 3600 years ago
https://www.science.org/content/article/ancient-people-china-systematically-mined-and-burned-coal-3600-years-ago
By Celina Zhao, Science.
Excerpt: Long before coal fueled the Industrial Revolution, ancient societies around the world were already exploiting its power to smelt metal or heat water for toasty baths. Now, excavations at a Bronze Age site in northwestern China show people were burning coal on a large scale up to 3600 years ago, 1 millennium earlier than previously thought. The research, reported today in Science Advances, also traces where the coal came from and how a shortage of other fuel may have encouraged ancient people to turn to this new energy source....