As Weatherford's book points out, fiat currency was not invented by the British, as the Chinese were using a similar system in the 1st or 2nd century, and continued to use a paper money system until 1399. Abuses destroyed the value of the paper currency, and it did not reappear in China until the 20th century.
This is accurate, but incomplete. Wikipedia has a decent page on the subject of fiat currency in the 18th & 19th century: http://en.wikipedia.org/wiki/Fiat_money#18th_and_19th_centur...