Coal has been around long before humans existed! We have been using it for thousands of years, in fact cavemen would burn coal to keep warm. Ancient Romans used coal in hypocausts. Hypocausts (below) were large structures under floors with a furnace. The smoke from the furnace would circulate through the enclosed area and the heat generated would seep up into the walls and floors of the room, heating it up. They were expensive to run so Ancient Roman’s only used them to heat public baths, baths in military forts and the villas of wealthy individuals.
Coal played a huge part in the industrial revolution, helping people power trains with the invention of the steam engine.