DECIMA - Digitally Encoded Census Information & Mapping Archive

Building the database

The DECIMA project uses data from three censuses of the city of Florence from 1551, 1561 and 1632. These three census have slightly different purposes: the first, a descrizione of the city and its inhabitants, allowed Duke Cosimo I de’ Medici to account for his population at the height of his power. The second, a decima property tax, allowed Cosimo to account for his population’s assets. The third, from 1632, allowed Cosimo’s great-grandson, Duke Ferdinando II de’ Medici to account for his surviving population following the major plague of 1630.

These three censuses are preserved in archives and libraries around Florence. You can find them in the Archivio di Stato di Firenze and the Biblioteca Nazionale-Centrale Firenze at the following shelfmarks:

1551: Archivio di Stato di Firenze, Miscellanea Medicea II 223

1561: Archivio di Stato di Firenze, Decima Granducale 3780-3784

1632: Biblioteca Nazionale Centrale-Firenze, Palatino E.B.15.2

Preserving these thorough but unique records with modern, searchable database technology has been challenging. The Decima records were initially plotted in a database using FileMaker. Our basic file was divided in categories or data fields, which were used to provide the frame for manuscript entries. In the creation of the database, there was an effort to standardize the various styles and orthographies of the three scribes, without losing the diversity of the document.

What does DECIMA mean?

The word ‘decima’ translates literally to ‘one tenth’ in Latin and Italian. The DECIMA Project takes its name from the 1561 decima tax, a 10% property value tax. DECIMA is also an acronym that stands for the Digitally Encoded Census Information & Mapping Archive.

Principal Investigator: Nicholas Terpstra

For more on DECIMA, please visit the project website.