The "Prosopographie der mittelbyzantinischen Zeit" is a comprehensive biographical dictionary of the eastern Mediterranean including Byzantine Italy in the early Middle Ages. It is published in two sections of five volumes documenting more than 20,000 persons in total. The first section covers the period 641-867, the second section 867-1025. In addition to the five volumes, each section includes not only a prolegomena volume, which covers the most important Byzantine and other relevant sources, but also a concluding volume containing lists of abbreviations, indices, adenda and corrigenda. Work on the second section will be finished by 2010.