The Reign of Emperor Vader (SW AU)

Following an attempted coup and successful assassination on Emperor Palpatine, Darth Vader is forced to rise to fill the role as sovereign of the Galactic Empire as he unravels a conspiracy and builds a new power base. As challenges old and new rise to challenge the power of the Empire, can the new Emperor keep his iron grip on the galaxy?? (Told from a pseudo-historical/in-universe POV)