The Five Worlds were a confederation of worlds, possibly located in the same star system. The primus inter pares amongst them was Antar. A stylized image of the Five Worlds arranged in a "V" shape, with Antar at the crux, served as the Royal Seal of Antar and the Five Worlds.
The precise relationship of the worlds to each other is unclear (it is unknown, for example, if they are all colonies of Antar or if they are all populated by members of the same species), but all of them seemed to bow in some form to the authority of Antar's royal family. For some time, there was peace amongst the Five Worlds, although they did on occasion suffer from the problems one might expect from living under a monarchial system of government.
In the early 20th century, the Five Worlds were plunged into chaos when the revolutionary Kivar stormed Antar's capital and slew King Zan, Queen Ava, Princess Vilandra and General Rath. Although Kivar cemented his hold on Antar, the other worlds refused to bow to his regime, even though several of them had had problems with King Zan's leadership. 60 years of civil war followed.
A peace summit was finally called in late 2000, with the leaders of the Five Worlds using human bodies to meet on Earth, the only neutral ground that could be agreed upon. At the summit, the Five Worlds agreed to Kivar's proposal that the alien-human hybrids of the Royal Four would serve as figureheads of a unified regime, while allowing Kivar and the other leaders to retain actual political power. Max Evans ultimately rejected the plan, and it appears that the fighting continued, particularly when the other leaders found out that Kivar didn't have the Granolith.
The current state of the Five Worlds is unknown.