There were three realms in the Arlish Galaxy, Highrealm which stands for Heaven, Midrealm which stands for the mortal lands, and Lowrealm for hell. Aru rules Highrealm as its Heavenly Emperor while Midrealm is delegated to the temporal Emperor. Lowrealm is ruled by the Emperor of Hell, which oversees sinful souls.
The world Midrealm was renamed to Voltrum by Ar Voltron, who evolved the entire empire of Arlish people to a Superman-like race, called Voltrumites. Voltrumites are superhumans, possessing spiritual supremacy and control over their spirit. They are enlightened beings who ruled over their empire, which spread all across the galaxy, with planet Voltrum as its heart. Voltron would eventually pass and the throne would be kept in custody by the Grand Regent.
The regent has denied every claim put forward by all Princes imperial, stating only a true royal can ascend the throne. Though the regent holds supreme power, no one but an Imperial prince can inherit the Voltrumite throne.
H.I.H. Crown Prince Paul of Voltrum 