Clearing out a drawer of papers today, we discovered two old banknotes, probably a gift from a far-flung relative many many years ago.
The astute reader will notice “Reserve Bank of Rhodesia” at the top of these; they were the banknotes hastily printed after UDI in 1966.
The Rhodesian pound became the Rhodesian dollar, which became the Zimbabwean dollar – which, famously, then was redenominated three times before effectively ceasing to exist last April, at a ratio of about 250 to the US dollar.
If we follow through each of the redenominations, taking the fiction it remains a functioning unit of currency, then… £1 10s Rhodesian turns into $3 Rhodesian, then $3 Zimbabwean, then – it rapidly becomes silly – $0.03 Zimbabwean (2006), $3×10-13 Zimbabwean (2008), and finally $3×10-25 Zimbabwean (2009); on 12th April 2009, the last day of it remaining in existence, it would thus be worth 1.2×10-27 US dollars, or just under 8×10-28 British pounds.
It’s hard to give the context for just how small that is. If you could somehow find an Indian ten-paise coin, probably among the lowest value currency units still circulating in any number, it’d be worth ~$0.0025; two trillion trillion times more than the nominal value of the two banknotes. (For comparison, the entire world economy is worth a mere thirty million trillion times the ten-paise coin…) The famous German post-WWI hyperinflation over three years only devalued the currency by 1012; this is quite literally a million million times worse. The only currency which collapsed further seems to be the Hungarian pengő, which over five years during and after WWII devalued by 1029.