Short answers, pulled from the story.
The word diplomacy originates from the ancient Greek term diplōma, meaning an object folded in two. This etymology reveals the practice's ancient roots in the physical protection of privacy, where sovereigns would fold documents to shield their contents before the invention of the envelope.
Some of the earliest known diplomatic records date back to the 14th century BC, when the pharaohs of Egypt's eighteenth dynasty exchanged letters with the Amurru rulers of Canaan, known as the Amarna letters. The Egyptian-Hittite peace treaty, concluded after the Battle of Kadesh in 1274 BC, stands as one of the first known international peace treaties.
Milan was the first to send a representative to the court of France in 1455, marking a significant shift from temporary envoys to permanent diplomatic presence. By the late 16th century, permanent missions had become customary, with Spain being the first to send a permanent representative to the Court of St. James's in England in 1487.
The Congress of Vienna in 1815 established an international system of diplomatic rank, addressing disputes on precedence among nations that had persisted for over a century. This congress, held after the defeat of Napoleon, aimed to resolve numerous diplomatic questions, including the shape of the political map of Europe and the disposition of political and nationalist claims of various ethnic groups.
Diplomacy is closely linked to espionage, with embassies serving as bases for both diplomats and spies. Some diplomats are openly acknowledged spies, while others operate under deep cover, gathering intelligence through illegal means, and deep-cover spies operating in many embassies are given fake positions.
Modern diplomacy employs a variety of tools and strategies, including counterinsurgency diplomacy, economic diplomacy, gunboat diplomacy, and hostage diplomacy. Counterinsurgency diplomacy employs diplomats at tactical and operational levels, often alongside military or peacekeeping forces, while economic diplomacy uses aid or other types of economic policy to achieve diplomatic agendas.