This was the innermost region of the galaxy, located around the giant black hole that was the center of the galaxy itself. The Deep Core was composed of a large cluster of star systems. Being so dense, the region was difficult to navigate through and there were few worlds that maintained contact with the outside galaxy.
During the Clone Wars, Jedi Master Yoda traveled into the Deep Core on a spiritual quest. He was guided by Qui-Gon Jinn to a nameless planet that was the homeworld of midichlorians and origin of all life in the galaxy.
During the Galactic Empire, the galactic government funded expeditions into the Deep Core, establishing an area known as the Deep Core Security Zone. Kren Blista-Vanee, a member of the Imperial Ruling Council was in charge of trailblazing new and stable routes into the region.