And here is the history of some of the planets:
Swanstrom
(Hive World/Sumitra Sub-Sector)
Swanstrom is one of the many Hive Worlds in the Aquila Sector and its dauntingly massive population makes up 2/3rds of the living souls within the Sumitra Sub-Sector. Thirty-eight billion people are scattered across eleven Hives, all under the rule of Noble House Linkara.
Its surface is an odd mix of blisteringly cold poles, barren and featureless sulphur deserts, and a tropical belt that is home to over six hundred thousand species of plant life. With no native wildlife, and no introduced animals having ever survived, the tropical forests of Swanstrom have become quite a tourist attraction for those that can afford it, and its night-time views of the enormous Tellegen Nebula are known throughout the sector.
The same beauty cannot be found within the Hives themselves, and all of them have extensive degradation, crime, corruption and, in some cases, significantly high levels of mutation in the lower levels. For this reason, an entire Commandery of the Order of the Dawn Blade is stationed on the planet, conducting periodic purges when unrest and recorded mutations reach a high level.
Symposa
(Hive World/Odirus March)
One of the first settlements within the Aquila Sector and the original capital world of the Odirus March, Symposa was once a mining world rich in ores and other materials considered to be extremely valuable by the burgeoning sector. With the Aquila Warp Storms making trade and the movement of materials so simple, the wealth of Symposa was quickly spread out across multiple worlds in every sub-sector, and through this world and others like it, the Aquila Sector thrived.
However, the days of Symposa’s continent-spanning strip mines did eventually come to an end as the richest deposits were drained of their worth and newer strikes became harder to find and less profitable. With the Administratum ready to abandon the world, leaving it as nothing more than a simple outpost, it was the outcry of the billions of mine workers that, for once, saw the Imperium have a change of heart. The great quarries and blast pits that marked the surface of Symposa were further excavated and became the foundations for huge Hive structures.
Within a three decades the vast seas of makeshift shanty towns and pre-fab buildings were replaced with thousand-mile high towers and spires, each housing several billion of Symposa’s population. The planet diversified, and machine shops were built. The hard workers of Symposa’s mines turned their efforts to creating weapons and munitions for the armies of the Aquila Sector, as well as turning out some of the best Imperial Guardsmen in the sector – the Symposan 63rd are a well renowned regiment that has fought across the sector for quite some time. The most promising Symposan cadets are often plucked from their barracks by the Emerald Vipers Chapter and given the chance to ascend to the ranks of the Adeptus Astartes. Truly Symposa is a rare success story within the Imperium – a world that had outlived its usefulness changed into a thriving society.
Of course, there is a much darker side to the Hives of Symposa. With the majority of its mineral wealth spent, the machine shops and munitions factories are only capable of producing their fine products with extensive imports of materials and consumables. This has led to money being one of the greatest driving forces within Symposan society. The truly remarkable Warp anomaly known as the Metallum Miraculum, far on the other side of the Aquila Sector, does keep the price of materials in check and helps to ensure planets like Symposa are never taken advantage of, but the people of Symposa never shy away from the prospect of quick and easy profits.
Crime is a major part of every day life, as what had once been the workers unions from Symposa’s mining days degenerated into the great crime syndicates that run the various Underhives. Murder, extorsion, slavery, theft, sabotage – these are day-to-day occurrences on the world of Symposa, hidden beneath the thin veneer of excellent craftsmanship and martial prowess.
There are very few pure souls on Symposa, and the concept of an ‘honest living’ within the great Hives is as alien to the populace as the Orks that have attempted to raid the planet on several occasions. On Symposa, greed is good, and virtually everyone is out for themselves in one way or another.
Nesol (Trading World/Maer Sub-Sector)
A virtually uninhabitable dustbowl, Nesol is a Trading World that acts as a drop off and pick up point for munitions, consumer goods and various other wares that pass throughout the Aquila Sector. A planet wide desert and an extremely slow orbit and rotational cycle makes most areas of the planet too hot to live in, and there are quite a number of native fauna that tend to be quite dangerous. For this reason the population is limited to Bayamón, the capital of Nesol, a number or orbiting settlements, and the tiny Gaoxin District, the furthest port settlement from the capital.
Nesol’s population sits at less than ten million, making it one of the most sparse populations in the Imperium, let alone the whole sector. The population is mostly made up of dock workers, traders, merchants and a vast bureaucracy that keeps the place running. Nesol is odd in that its Tithe Grading is listed as Adeptus Non. It has a PDF, but is not expected to raise Imperial Guard regiments.
The truth behind this is that Nesol is a bit more than just a Trading World. The population lives mostly in low-level dwellings, with the Bayamón high-rise reaching its peak at a single 5-story building at the centre of the city. This is because most people on Nesol live and work underground, in specially excavated houses. It is these houses that hold Nesol’s secrets – the underground munitions storage facilities. Nesol is deliberately not classified as an Armoury World in order to keep some level of the Imperium’s strength a secret, especially given the large amount of pirates that operate within the Aquila Sector. If anyone was to ever learn the truth of this small sandy world, every pirate with half a brain cell and a decent blockade runner would be coming to the planet looking for their payday.
The history for the planet of Andronicon - bottom right-hand corner on the map - is too long to post, as it is currently over 12,000 words and isn't finished.