Commonwealth was discovered by long-range telescope in 2045 and confirmed to have an oxygen-nitrogen atmosphere in 2090. It was reached by wormhole in 2110.

The planet's wide temperate belt is dominated by a single large continent in the early stages of dissolution, similar to the breakup of Pangaea on Earth 200 million years ago. Much of the interior of the continent is frigid tundra, too distant from the moderating influence of the planet's great ocean. But along the coasts, the continental dance and the movement of ancient glaciers have carved a vast array of lush valleys into the landscape. Far at sea are two massive hurricanes; Scylla and Charybdis, (Categories 6 and 4, respectively, in the expanded Saffir-Simpson scale). Like the Great Red Spot on Jupiter, they are permanent features. There is no evidence they have neve made landfall. These are the locations of the only known forms of life evolved to live entirely within a storm system.

Commonwealth is classified as a Terran Gaean world. It has a well-developed ecosystem that includes multicellular life, including complex plants and animals.

The primary predator in the habitable coastal and fjord regions was described by the first colonists as a "rolling fang" -- an armored, wolverine-sized pack hunter that lives on the clifftops. They attack grazer animals by rolling themselves into balls and plummeting down hillsides, crashing into the herbivores, often knocking them over and stunning them. They then unroll themselves and strike.

Fortunately for the colonists, Commonwealth's life evolved using a different set of proteins, leaving Earth-life indigestible to the rolling fangs. Occasionally, though, a fang pack has mistaken a group of humans or their herd animals for the native cuisine, and attacked. Ranching on Commonwealth is therefore a precarious job at times.

Another unique animal is several species of airborne "Monties," which propel themselves in a manner similar to hot-air balloons.

The current population is estimated at 2.1 million. Overruling China's protests, the U.N. designated Commonwealth for "open" colonization in 2110. Citizens of any nation were allowed to immigrate under an international lottery system, and the world would be run under a single, U.N.-designed republican government. Social scientists hoped to create a truly mixed world, free from nationalist, ethnic and religious strife.

The design failed. Less-than-hoped-for investment in the petroleum sector reduced economic opportunities, and ethnic and religious identity groups began agitating for increased autonomy from the central government. In 2125, an unidentified group bombed and destroyed the main assembly building in Unity City, which set off a nearly planet-wide civil war.

Today, the U.N. has no presence on the planet. An estimated 45 states of various sizes exist on the surface. A few have achieved a measure of stability and are seeking formal recognition as nations; most are ruled by warlords or not at all.

Weapons imports are prohibited by United States law. Travel to Commonwealth is not advised for any person.

The planet has three moons. Rodrigo, named for the planet's first colonial governor, is large enough to hold a thin carbon dioxide atmosphere. The other two moons are captured asteroids. The planetary refueling station at the L-4 position with Rodrigo.