Fortress world

A Planety which became "bristling iwht firepower" and the planet had many shields, Golan defense platforma, large defense fleets, etc.

the Clone Wars fortress worlds were CIS worlds protected by thoussands of CIS warships and billions of battledroids

After Coruscant was re-taken by the Empire, the Core Worlds and became fortress worlds (the Deep Core became fortress worlds after Endor) and that allowed the Imperial civil War to happen