The records of historical prototypes of diplomacy are rich with examples, but little systematic analysis. Examples include the delegations sent by various Chinese states to each other prior to the imperial unification of China in 221 BC, the evidence in the al-Armana tablets sent between Egyptian pharaohs (Cohen and Westbrook, 2000), the Babylonians, and other polities that occupied the Middle East in the second millennium BC, the more highly articulated diplomatic practices of the Greek city-states, and the regularized procedures for foreign contacts in the Byzantine Empire (cf., Holsti, 1967: ch. 2; Hamilton and Langhorne, 1995; Ferguson and Mansbach, 1996). The practices varied according to local customs and changed over time, but there were rough similarities across cultures. These included the sending of emissaries of high rank; considerable ceremony attending the arrival and departure of delegations; great concerns over the rank and status of sending and receiving parties; and various forms of diplomatic immunity. The last constituted a type of universal norm across cultures but in ancient polities, the norm was frequently violated. We know of numerous instances where messengers were put in captivity or executed by their ostensible hosts.

Early diplomatic prototypes lacked the essential ingredients of an international institution. There were fairly regularized practices within and between cultures and diverse polities, but they lacked a set of defining ideas that gave the practices a distinct and commonly understood meaning.