British pound (GBP)

① As the UK’s official base currency at the outset: the Bank of England was founded in 1694 and began issuing pound banknotes; the standard system has continued to this day.
As of 2026: it has been in existence for 332 years, making it the oldest sovereign currency still in circulation worldwide.
② The complete end of the gold standard and fully credit-based fiat currency: in 1931, the UK abandoned the gold standard.
Pure fiat period: 95 years, far higher than the 27-year average.
The pound’s purchasing power has shrunk by 99.7%. In essence, it is long-term slow depreciation; there has not been a collapse-level inflation that would completely invalidate it—its purchasing power has simply dropped dramatically, so it remains in circulation.