The accounting system behind modern business was first printed in 1494

Modern finance rests on a deceptively simple idea: every transaction is recorded twice, as both a debit and a credit, so the books always balance. This is double-entry bookkeeping, and it emerged among the merchants of Italy’s commercial republics, with instruction manuals circulating in various Italian cities during the 15th century.

The system reached a wide audience through the Italian mathematician and Franciscan friar Luca Pacioli. His 1494 mathematical treatise, the Summa de arithmetica, printed in Venice, contained the first published description of double-entry bookkeeping.

Pacioli did not invent the method; he documented the practice already used by Venetian merchants. But by printing it in plain Italian, he turned a merchants’ trick into a teachable discipline.

For that, he is often called the “father of accounting.” The double-entry logic he described still governs the ledgers of businesses and governments today.