The double sestertius was a large Roman coin made of orichalcum (brass) first issued by Trajan Decius in AD 249-251, as a response to the inflationary pressures of the time which had devalued the buying power of the conventional sestertius. In reality the new coin was little bigger than the traditional sestertius, which by then was being manufactured at a lower weight and smaller size than it had originally been, and was not a success.