The Catalogus Baronum or Catalogue of Barons, is a registry recording the military obligation owed by the Barons of the Kingdom of Sicily. Written during the twelfth century under the reign of Roger II and expanded during the thirteenth. The registry contains over a thousand entries that include the names of barons, the sum of their obligations and where their fiefs were located. These knights were owed to the crown, but were managed by either a constable or a count.

Which towns or cities in parts of Apulia do we see the most fiefs and which constable or count managed the largest number of soldiers?

The register was written entirely in Latin and currently lacks a database of any sort. One would need to translate and organize hundreds of entries to meaningfully use the register. Drawing from the modern critical edition by Evelyn Jamison, this project does just that and records the first 99 entries into a searchable database (these locations are organized by modern communal boundaries. I might add a correlating map that shows the quantity of knights owed and from where). Though difficult to access, the document provides information regarding the lordship, and royal administration of the mainland kingdom. The ability to access this information more easily will allow scholars, who lack the extensive training required, to meaningfully interpret and contribute to a large conversation about the kingdom of Sicily.