Cuneiform diplomacy

The term “cueinform diplomacy” refers to the “diplomatic system used between Near Eastern kingdoms from approximately 2500 to 500 BC; so named because it was based on the exchange of communications printed on tablets in cuneiform characters.” The system had its own la, customs, and protocol in addition to using a common language. The basic principles of contemporary diplomacy are comparable to those of the cuneiform system of antiquity in terms of demands and procedures. Source: Berridge, G. R., & James, A. (2001). A dictionary of diplomacy. Palgrave.
See also: Amarna diplomacy