Laumer (World 66)
Keith Laumer (1925 – 1993; first SF publication, 1959) is best known for his Bolo and Retief series. The Bolos are self-aware super tanks, and are the literary forefathers of tanks such as Steve Jackson Games’ Ogres. He also wrote the Imperium series (in which Brion Bayard must travel to an alternate dimension to stop his alter-ego, the dictator of North America), The Lafayette O’Leary series (in which Lafayette is transported from normal life to the feudal world of Artesia and its beautiful princess Adoranne), and another twenty stand-alone novels.
Jame Retief, galactic diplomat extraordinaire in the CDT (the Corps Diplomatique Terrestrienne), is born from Laumer’s years in the foreign service during the Cold War between the US and the Soviet Union. The CDT is a thinly disguised US Foreign Service, while the alien Groaci fill the roll of Soviet diplomacy. The premise is thin enough that any attempt to make either service superior to the other would be uninteresting; instead, Retief constantly (and amusingly) finds way to accomplish a diplomatic resolution to each crisis despite the parameters of protocol on either side. He is just as constantly reprimanded for violating that protocol, even when saving the day.
Diplomats
Of all the authors and series in this list, Laumer’s diplomats of the CDT are the obvious choice of the Emperor to dispense His Imperial Will. Therefore, Laumer is the Imperial capital, from which the Emperor sends forth his diplomatic corps.