Jemdet Nasr is a historical and cultural period affiliated with southern Mesopotamia thought to have lasted from 3200-2900 BC. It is a relatively new archaeological period to be recognised thanks to discoveries by the University of Oxford in 1925, who came to discover a diverse range of material remnants at the site of Tell Jemdet Nasr. This suggested a distinct and impressive urban community that existed between the Late Uruk and Early Dynastic periods.
As a developed and interactive community, people living during this time fashioned stone tablets and seals with cuneiform inscriptions, impressing pictures and descriptions into soft, prepared clay. These seals guaranteed the authenticity of marked ownership, becoming instrumental in legal transactions, protecting goods against theft, and corresponding with other Sumerian administrations.
For more about stamp seals, see our relevant blog post: Making their Mark: A Concise Guide to Western Asiatic Stamp Seals