Alpha Centauri

Mankind's first extrasolar venture, Alpha Centauri has a long and storied history full. Much of it full of internal conflicts brought with it from Earth in the way of competing colony missions with an adversarial relationship with one another.

Proceka

Originally meant to be settled by a ship called the Glorious, and planet was to be named Gloria as a result, a different expedition launcher a few years later but with better engine technology passed them by and settled the planet first, naming it Proceka and stealing the primary landing site the Glorious mission intended to use. The Glorious mission arrived a few years later and settled at an alternative landing site instead, dubbing it Gloria Apex.
This was the start of a long history of animosity between the two colonies, leading to armed conflict between the two in -318 New Standard. The fighting was fierce and risked the destruction of both colonies, but in the end the Procekan colonists won and absorbed Gloria Apex.
Modern Proceka
Proceka is the most densely populated planet outside of the Sol system, in large part because it can afford to be. Proceka was an ideal world for terraforming, with a strong magnetic field, atmosphere within spitting distance of breathable, and a simple microbial ecosystem that was easily subsumed by more advanced earth bacteria. Proceka made a breathable atmosphere well ahead of schedule, soil reclamation proceeded wonderfully and now the planet has a functional ecosystem and farmland as well as open-air cities. The ecosystem development project continues, slowly introducing new plant and animal life, but many regions could be mistaken for the fertile soil of Earth.
In terms of population, there are three distinct groups: those who identify as Procekans, the Glorians, and the Twins.
The Procekans are the largest, most influential portion of the population, and the ones with the most power. Not all of them are actually descended from the original colony mission, but they are what is generally considered to be the Procekan people and the Procekan culture.
The Glorians are a stubborn minority, mostly concentrated in Gloria Apex. There is a lot of resent there about Proceka and their 'stolen future'. While they have no enforceable claim, the myth endures that the planet was theirs by right and some day they will reclaim what has been taken from them, the 'Glorian Dream'. Radicalized groups of Glorians have grown less common over time, but it is a danger that has never really gone away. Any time that Proceka appears week, Glorian dissent rises to a boil.
The Twins couldn't care less about the conflict. They are refugees of the Twin Systems, luck enough to have the means to get to Proceka after the Succession and plead asylum. They have no desire to go home, and do not support the Glorian Dream at all. They are just trying to get by. Given the vast land for the taking on Proceka, the Twins generally have done quite well for themselves, though they are typically scattered in smaller settlements across the planet rather than living in the established cities.
The Cradle and the Skyboard

Proceka's orbit is marked by a collosal vanity project known as the Cradle, which is a space-elevator alternative. Essentially, a thin mental rail forms a complete ring around the equator of Proceka, and on that rail rides the apparatus that moves the Cradle. The Cradle itself is a mile wide, 2 mile tall structure with a rounded stone base that is lowered from orbit to rest upon the surface of Proceka by a system of pulleys and more than 400 individual cables. There are 12 designated landing zones for the Cradle that form a ring at regular intervals around Proceka (three of which are artifical islands out at sea to complete the ring), and the movement up and down of the Cradel in its oscillations land it in each of these zones in turn for over an hour before it is pulled back into the sky on to the next landing zone.

A second smaller station, known as the Skyboard, forms the counterweight for the Cradle. When the Cradle is on land, the Skyboard is in orbit. With the Cradle rises, the Skyboard lowers into the upper atmosphere of Proceka. While the Cradle can load and unload from the ground, the Skyboard instead is essentially a flying airport that takes passengers from high altitude craft up to orbit, and bringing passengers from orbit down to depart on aircraft to their specific wordly destination.

The Cradle is a thoroughly Ruskinite design, dating back to a famous project proposed by Tam Ruskin during the martian frontier era. While it was never implemented on Mars, the idea was resurrected centuries later on Proceka, though it was not actually produced according to Ruskinite doctrines eschewing mass production.

Tugarin

Tugarin is a large gas giant, known for its destinctive blood-red coloration when viewed from afar. It orbits as the 6th planet in the Alpha Centauri system as measured by stellar cartographers, far out from the habitable zone. Tugarin has a mass of 87 gravities, meaning that it is a bit smaller than the planet Saturn. Tugarin is orbitted by 51 registered moons.