Excavations in the ancient city of Eridu have revealed a grand palatial structure identified as a 'Diplomatic Residency' from the Early Dynastic period. The building contains specialized quarters for foreign emissaries and a massive archive of bullae—clay envelopes used to secure trade goods. Most significant is the discovery of Harappan-style cylinder seals and carnelian beads originating from the Indus Valley.
These artifacts confirm a high level of formalized diplomacy between the Sumerian city-states and the Meluhhan (Indus) civilization. The architectural layout of the residency features communal dining halls and central courtyards, suggesting that diplomatic visits were accompanied by elaborate state banquets and ritual gift exchanges.