Were there any Medieval or earlier financial scams on a massive scale?

drewbenoit:

racefortheironthrone:

There were certainly financial scams, but I don’t know of any that were on a massive scale. Mostly because economies were much more localized in the Medieval period, so there’s less opportunity/ability to conduct any kind of economic activity across entire countries or internationally. 

the south sea bubble

A major financial scam, to be sure, but definitely not medieval, taking place as it did in the early 18th century.