When was crude oil first refined?

Answer 1

There is no easy answer to this question because it is so broad. Petroleum can be refined into a multitude of substances. Although the first recognized commercial refinery is widely believed to have been in the late 1850's, there is ample evidence to show the advent of the refining of petroleum for kerosene nearly 1000 years earlier in the ninth century by the Persian Razi (or Rhazes). Further, if you allow for natural refinement, naphtha and similar products were used in warfare by both the Greeks and Romans, and probably before. If you would like to refine your question, perhaps someone can give you a more precise answer. So, to answer your question as asked, "Crude oil was first naturally refined in prehistoric times, and was used for things such as water proofing, building (adhesives), fuel, and medicine."