The Core People live in the centre of the Earth on Earth-5391 a reality where the Earth is apparently hollow and contains a smaller micro "universe" inside where the Core People reside. They apparently lived below the surface of the Earth for centuries undiscovered until the year 2075. In that year the Core People went to war against the surface world due to drilling and salvaging minerals out of the Earth. The attack was repelled by the Space Sentinels, whose leader Speed Carter, his sidekick Johnny Day and girlfriend Stellar Stone were contacted by the Core People's leader Nikka who claimed the surface people were invading their home planet. Carter and his companions then traveled to the centre of the earth and made peace with Nikka and his people, and made a trade agreement when he realized that his people were plundering the Core People's domain.
Shortly after a peace agreement was formed, the Saturnians attacked the Earth. But thanks to their new alliance with the Core People, the Space Sentinels were able to launch a surprise attack and repel the invaders.
Type of Government
The Core People are governed by a "guardian" who acts as ruler and defends their people.
Level of Technology
Advanced within the confines of their domain, they have developed air transportation. They have also invented "geyser-guns" that fire jets of water that is hot enough to melt through durable metals as well as spider-like tanks that can burrow through the ground.