The Seleukid kingdom was one of the greatest states of the ancient world, stretching from Greece to India; it is also one of the least known. This reference work lists all the people whose names are known who lived in that kingdom, classifying them into rulers, officials and subjects, and in each case noting their activity. In addition all the foreigners whose lives affected the Seleukid state are listed. The gazetteer also lists the places which were included in the kingdom, classified as regions, including provinces and peoples, or settlements, whether cities or villages, with a description of their place in its history. The institutions of the kingdom, the social and political ethos which made it work are also noted and briefly described.