It was once known as "oil of vitriol". This name was created by Jabir ibn Hayyan, the person who discovered it. It used to be prepared by the reaction of potassium nitrate with sulfur. This reaction would produce sulfur trioxide which would dissolve in steam to produce sulfuric acid. Then this reaction was done in lead containers. The contact process, the most common process, was invented in 1831 and is still used today.