What are Imperial Daleks?

During the Imperial-Renegade Dalek Civil War, two Dalek factions emerged who fought against each other for control of the Dalek Empire. The Imperial Daleks, a new race of Daleks who serve their creator Davros, fought against the Renegade Daleks of the old Dalek regime. But what is the in-universe history of the Imperial Dalek faction?
All footage is the property of the BBC. Music by Frank Klepacki