Casa di San Giorgio turned Genoa's war debt into tradeable shares

After its defeat by Venice in the 1380-81 War of Chioggia, the Republic of Genoa was left owing a tangle of separate public loans, or compere, to the private citizens and syndicates who had financed the war, many paying 8-10% interest the state had no realistic path to servicing as scattered individual obligations. Every attempt to negotiate down or restructure debt piecemeal ran into the problem that each compera had its own lenders, its own terms, and its own political constituency demanding repayment first.

The obvious moves — default, or raise taxes hard enough to pay everyone back — were both politically and financially catastrophic for a trading republic that depended on the same merchant families it owed money to for its future credit. Genoa needed a way to make the existing debt tolerable to hold indefinitely, not a way to pay it off.

Chartered in 1407, the Casa di San Giorgio consolidated Genoa's separate war-debt compere into one institution and converted the state's obligation into standardized shares called luoghi, each a claim not on a repayment date but on a specific ongoing tax revenue stream (customs duties among them) the Casa itself was granted the right to collect directly. Holders no longer waited to be repaid; they held a tradeable instrument yielding an income stream and could sell it to someone else for cash whenever they wanted out.

Consolidated the debt into tradeable shares backed by tax revenues the Casa collected, letting holders sell their claim for cash instead of waiting for repayment.

Consolidating scattered loans into one standardized instrument created a liquid market.

Backing shares with specific tax revenue made them credible and valuable.

Tradeability let creditors get cash by selling, not by waiting for state repayment.

The revenue stream was durable, so the instrument held value for centuries.

When debt can't be repaid, make it tradeable: back it with a credible revenue stream so creditors can sell out instead of waiting for repayment.

The luoghi traded as a liquid asset among Genoese and later international investors — accounts were later held by figures including Christopher Columbus and Emperor Charles V — turning what had been an unpayable pile of state IOUs into a functioning market instrument that outlived the immediate war-debt crisis by centuries.