Cartullarium Massariorum of 1340: A Logical-Analytical Reconstruction of the Budget of the Commune of Genoa

Subject. The Cartullarium Massariorum (Book of the Massari of the Commune of Genoa) for 1340 remains the earliest known example of the application of double-entry bookkeeping in public accounting. However, until recently, its accounting system had not been fully reconstructed, and researchers had been limited to the analysis of individual accounts. The purpose of the article is to present a comprehensive model of the accounts associated with the summary income and expenditure account of the Commune ( Communis Janua ) and, on this basis, to characterize the structure of Genoese public accounting. The study employs the method of flowchart-based logical-analytical modelling (reconstruction) based on the original manuscript preserved in the State Archives of Genoa. A digital methodology was applied, including digitization of the register and the development of a specialized database-driven program capable of automatically restoring missing entries through corresponding accounts. The findings demonstrate that the reconstructed model consists of eight levels, ranging from the Commune’s summary account to accumulated expense and loss accounts. The accounting records were maintained without a Cash account, using personal accounts of the massari , which reflected their liabilities to the Commune. Budget revenues were generated exclusively from taxes and duties, while expenditures were accumulated through single-phase chains of accounts. The scientific contribution of the study lies in the first-ever reconstruction of two missing debit entries in the summary account, which had previously been interpreted as a single illegible amount, as well as in the clarification of the number of expenditure items. The chronological alignment of transactions revealed a consistent sequence of accounting operations within the financial year. The study concludes that the Communis Janua account represents the earliest surviving income and expenditure budget prepared using the double-entry system, while the accounting system of the Commune as a whole corresponds to a stage in the evolution of double-entry accounting that preceded the emergence of full-scale double-entry bookkeeping.