What is agent of byzantium?

Agent of Byzantium is a science fiction novel written by Harry Turtledove. It was first published in 1987. The book is set in an alternative history where the Byzantine Empire never fell and remained the dominant power in the world. The protagonist of the story is Basil Argyros, a Byzantine secret agent who is tasked with investigating and solving various threats to the Empire. The book presents a vivid portrayal of Byzantine society, culture, and politics, as well as a range of historical figures, including Emperor Vasilios II, Patriarch Photios, and the founder of Islam, Muhammad. The novel has been praised for its detailed world-building, intricate plotting, and fascinating characters.