The goal of the Prosopography of the Byzantine World Project, formerly known as the "Prosopography of the Byzantine Empire" (PBE), is to record in a computerised relational database all surviving information about every individual mentioned in Byzantine sources during the period from 641 to 1261, and every individual mentioned in non-Byzantine sources during the same period who is 'relevant' (on a generous interpretation) to Byzantine affairs. The project covers the period from 641 (the terminal date of Volume III of the Prosopography of the Later Roman Empire) to 1261 (the commencement date of the Prosopographisches Lexikon der Palaiologenzeit).
The six-hundred-year period is divided into three roughly equal sections: 641 to 867; 867 to 1025; and 1025 to 1261. The work of the project begins therefore when the Byzantines were struggling to cope with the Arab conquests in the Levant and the spread of Islam, and ends with the restoration of the Empire in 1261 after the loss of Constantinople to the crusaders and the period of exile in Nicaea.
PBW was established as a British Academy Research Project in 1989. The project is housed in the School of Humanities at King's College London and is based in the Centre for Computing in the Humanities (CCH), which provides its technical support. It is funded by the AHRC and the British Academy. PBW works in collaboration with the Berlin-Brandenburg Akademie's Prosopographie der mittelbyzantinischen Zeit (PmbZ) and the Evergetis Project.