Naming of moons underworld, and Nix (a respelling of Nyx), mother of Charon, is the goddess of darkness and the night. Kerberos is a giant three-headed dog who guards the entrance to the underworld. The fifth moon is named for the river Styx that forms the boundary between the worlds of the living and the dead. The name of Eris's moon Dysnomia was suggested by its discoverer Michael E. Brown, who also suggested the name of the dwarf planet. The name has two meanings: in mythology Dysnomia (lawlessness) is the daughter of Eris (chaos). However, the name is also an intentional reference to
Rebellion of the Three Guards Dan, the Duke of Zhou, declared himself regent and took over the court. This aroused the anger of the Three Guards who suspected Dan of usurpation and believed that they should serve as regents. Allied with many separatist eastern nobles, Shang loyalists under Prince Wu Geng, and several Dongyi and Huaiyi states, they rose in rebellion against the Duke of Zhou. The latter then launched a second "eastern campaign" to put down the rebellion, and defeated the rebels in three years, killing or disempowering their leaders. In doing so, he also further expanded the Zhou kingdom into eastern China, transforming