Spread of double-entry bookkeeping

Timeline

1. 1289–1290Genoa · GenoaGenoese merchant ledgers began recording the same transaction separately on debit and credit sides, facilitating reconciliation of overseas agency, bill of exchange, and inventory accounts, reflecting the practical need for double-entry thinking in complex cross-border trade.
2. 1290–1300Florence · TuscanyDocuments such as the Florentine Farolfi ledgers of the late 1290s show more systematic per-account double-entry structures, indicating the bookkeeping method spread along the Arno-Mediterranean trade routes to Tuscan banking centers, laying the foundation for later Medici family finance.