Agent of Byzantium is a 1987 collection of short stories by Harry Turtledove, centered on the exploits of Basil Argyros, a Byzantine secret agent. The stories are set in an alternate 14th century, where Islam never existed and the great ancient empires of Byzantium and Sassanid Persia survive.

Jurchen is a term used to collectively describe a number of East Asian Tungusic-speaking people. They lived in northeastern China, also known as Manchuria, before the 18th century. The Jurchens were renamed Manchus in 1635 by Hong Taiji. Different Jurchen groups lived as hunter-gatherers, pastoralist semi-nomads, or sedentary agriculturists. Generally lacking a central authority, and having little communication with each other, many Jurchen groups fell under the influence of neighbouring dynasties, their chiefs paying tribute and holding nominal posts as effectively hereditary commanders of border guards.