Ever since money first circulated, counterfeiters have forged money with the aim: usually, of making profits at the expense of the issuing authority, the individuals to whom the forgeries are passed, and the community generally but also: at certain times in history, to make up for shortages of official money occasionally, during times of war or conflict, to destabilise governments in the case of faked rare, old coins, to deceive, and make money from, collectors. In some past societies, genuine and forged money have co-existed. In Imperial China and Roman Europe, for example, imitation and forged coins supplemented the official money supply. In the US in the middle of the nineteenth century, one third of all the currency in circulation was estimated to be counterfeit.