The Periphery is a fictional location in Isaac Asimov's "Foundation" series and refers to the outer rims of the Galactic Empire, including planets such as Anacreon and Santanni. Imperial control is weakest in the periphery, as planet governors there frequently possess their own fleets. Santanni revolts during "Forward the Foundation". About 50 years after the First Foundation is established on Terminus, the emperor will grant the periphery autonomy. This effectively removes them completely from Imperial control, making the dissolution of the Empire far more apparent than it had been before.