Fugger priced his charity's rent in a fixed coin, not a currency

In 1521, the wealthy Augsburg merchant-banker Jakob Fugger endowed a walled housing complex for the city's needy Catholic workers, specifying in the foundation deed that it should exist 'in perpetuity.' Anyone setting up a fund meant to run for centuries faces the same structural problem: whatever payment is fixed as fair today will not stay fair. Currencies get replaced, prices inflate, and a rent reasonable now is either worthless to the landlord in a hundred years or unaffordable to the tenant, forcing a renegotiation that can compromise or collapse the original arrangement.

The standard way to keep a long-term payment meaningful is to index it — tie the rent to inflation, peg it to a basket of goods, or simply plan to periodically renegotiate as conditions change. Every one of those approaches requires someone, at some future date, with the legal authority and institutional continuity to actually carry out the renegotiation — an assumption that gets shakier with every century, currency and government that intervenes.

Fixed the rent as a nominal token, one guilder, unindexed, so inflation couldn't erode it and no future renegotiation was needed.

A fixed nominal amount converts arithmetically across currency changes, with no judgment call.

The rent was symbolic, not the funding source, so its erosion didn't threaten operations.

The deed made the number legally load-bearing, preserving tax exemption without renegotiation.

For obligations meant to outlive currencies, fix a nominal token rather than index to inflation, so no future renegotiation is needed.

Five hundred years, several currency changes and multiple German states and governments later, residents of the Fuggerei still pay the equivalent of one guilder — about 0.88 euros — a year, plus the same three daily prayers, unchanged since 1521. The complex now houses about 150 residents across 67 buildings and 142 apartments and is financed not by rent, which covers essentially nothing, but by returns on the foundation's own forestry and real-estate holdings — roughly 70 percent from forestry alone.