Son Altesse Sérénissime (His Serene Highness) or SAS is a series of espionage novels created by French author Gérard de Villiers, featuring Austrian prince Malko Linge as the main character.

He began writing the SAS novels in 1964, when an editor told him that Ian Fleming had died and that de Villiers might create the next James Bond.

[1] Government officials and intelligence officers, who enjoyed seeing themselves fictionalized and reading about events they could not reveal publicly, told de Villiers secrets that appeared in SAS, making the series' plots and settings unusually realistic.

A Lebanese intelligence officer who wanted to reveal information but did not trust journalists (including Worth) helped de Villiers, the novelist said.

[1] In order to finance the repairs of his castle in Liezen, Austria, main character Malko Linge works as a freelance agent for the CIA of the United States.