"The origins of diplomacy date back at least to the Bronze Age in the Near East. Caches of documents from the Euphrates kingdom in the mid–eighteenth century BC and from Akhenaten’s Egypt four centuries later reveal a regular exchange of envoys with neighboring states, prompted by the need for trade and the danger of war. This was hardly a fully fledged diplomatic “system.” Envoys were not resident ambassadors and they were not protected by agreed rules of immunity—but it was a recognizable form of diplomacy. Summitry, as we would understand it, was rare, being mostly confined to visits by minor rulers to pay homage at the courts of their overlords. This is hardly surprising because of the travel time required—six weeks for even a fast courier from Egypt to Babylon—and because of the hazards and insecurities en route. For a ruler to undertake such a journey was therefore a sign of his inferior status. Rulers of great powers, though they might address each other in letters as “dear brother,” would never meet unless one of them had become the booty of battle, which was not summitry but submission."