Vitam is the home planet of the Crested Serpents. The land on Vitam is made up almost entirely of jungle, with the exception of it's frozen poles.
Vitam is home to a huge array of dangerous and complex life forms.
When human's first colonized Vitam during the Age of Strife the people soon learned that they couldn't establish any communities larger than about 50 people without them being attacked by whichever Hadracus territory they were infringing on.
Rather than bringing in military force to wipe out the all the Hadracus, research stations and training camps were set up underground.
During the planet's extended isolation from the rest of humanity, civilization slowly disintegrated and the human population became spread across the planet into numerous tribal communities.These tribes came to worship the mighty Hadracus. Killing a Hadracus was beyond the capabilities of these people so they instead looted nests for scales and toxic blood.
When the planet was discovered during the Great Crusade the local population were of interest. The hundreds of underground research facilities had been overgrown, and the only sign of civilization were numerous isolated tribal camps.
Although tribal, the locals were far from mindless. Most were intelligent and keen to share their knowledge with the Imperial troops. The local people were no threat and embraced the Imperium gladly. An Imperial convoy was sent down to begin building modern communities and establish training camps.
Their first attempt was a disaster. Although they had taken the local people's warning into consideration, they were not ready for the incredible attack launched on them by an agitated Hadracus.
Their next establishment was built far more carefully. The base was built underground in a thick concrete bunker. Over the net few years the base expanded underground like the roots of a huge tree. The ever growing imperial presence underground was virtually invisible above surface.
Within 30 years of the planet being re-colonized, the underground city had spread to a diameter of over a kilometre. The city was named Nidum. The city continued to expand for the next hundred years until the Horus Heresy.
By the Horus Heresy, the Imperial presence on Vitam was quite extensive. some of the ancient research facilities had been discovered and re furbished. Nidum had grown even further. The scientists on the planet had started to understand the ecology of the planet.
When word reach Vitam that civil war had broken out, many of the troops stationed there were forced to leave. The generous funding that the research facilities were receiving was drastically cut. Nidum's expansion slowed to a halt.
Although a scientific presence was maintained on the planet, little progress was made.
It wasn't until the middle of M36 that Vitus was given another chance. A detachment of Space Marines had been sent to the planet in pursuit of a fleeing Ork Warboss. After cathcing up with and killing the desperate Ork, the Space Marines reported back to their Chapter. Knowing his Chapter was soon to be taking part in a 19th Founding, Captain Nedracan informed his superiors that Vitus would make an ideal home world for a new chapter.
Two years later Captain Nedracan was brought in front of a high council and informed that he would lead a new Chapter of Space Marines based from Vitas. Nedracan was given time to prepare and plan his chapter. He selected a number of his most trusted brothers to join his command.
Over the next few years the Chapter constructed a Fortress Monastry on Vitus. Their Monastery was based in Nidum as it was the closest thing Vitus had to civilization. After being exposed to the local people and wild life Nedracan decided to name his chapter the Crested Serpents in honour of the mighty Hadracus that guarded their jungles.
Almost four millenia later and Vitus had barely changed. Nidum was still the only real civilization on the planet. The City had expanded further but was still barely visible from the surface. Many of the old research stations stations had been re-fitted.
Thousands of tiny tribal communities were still dotted over the planet, regularly being used to recruit new marines.