Following investigation, interrogation of fallens" and - most important proof scraps of materials brought by assault parties from wreck of Galatea" convinced Dark Angels about fatal mistake. There was little that could be done- entire crew of cruiser has been posthumously added to lists of honored battle brothers lost in wars with Chaos, thus ending "Galatea's" history in official records.
On the surface of the planet, hidden from outside world, survivors tried to survive in deadly environment. What was left from original crew were 76 battle brothers, three sergeants, two chaplains, apothecary and techmarine. Geneseed gathered from some of bodies allowed to harbour hope of rebuilding chapter destroyed- as survivors believed- by followers of Dark Gods. During next ten years on high plateau overlooking jungle crude fortress- monastery has been built. Materials salvaged from wreck- shield generators, adamantinium plates, some of the cannons and modified torpedo launchers have been used to secure new home of survivors.
Styga was a deadworld due to two factors- it's tropical weather with almost constant monsoon winds making any agriculture virtually impossible and deadly wildlife, which, combined with lack of mineral resources made colonization of the planet extremely hard and- after first attempt during first crusade- planet has been left as poor and unimportant from both economical and strategical point of view.
First contact with local population was legendary now "walk through coals". Watch on outposts located on borders of jungle informed HQ about huge dark cloud of smoke slowly approaching monastery. Huge jungle fire started by volcano eruption left only one way of escape through the plateau on which Penitents fortress has been located. For three days battle brothers have been fighting off constant attacks of fear-mad giant reptile-like creatures. At the end of third day, when fires were raging almost below armored walls a single human has been spotted. It's been a uncouncious, 8 years old child, strapped in crude saddle on the back of two legged beast. It's body has been painted blue and smeared with some kind of sharp-stinking mass, head protected by helmet made from scull of predator. Immediately after receiving info about this discovery chaplain ordered sending party of twelve battle brothers encased in terminator armors in search for traces of any human activity. Fires were dying now, what was left from once mighty jungle was but a sea of gray coal, glowing red with each move of wind. Surprisingly after two days march rescue party noticed a spot of green on horizont. As they discovered later human settlements protected themselves by firing counter fires and remained in huge part intact by fire. Clad in black armors, red eyed humanoid shapes coming out of ashes made god-like impression on tribal population of Styga and very quickly perilous travel through the jungle to the "house of gods" replaced initial rites of old, thus ensuring flow of recruits to chapter. In exchange Penitents provide what must be god-like care, training and protection to their followers.
Having witnessed end of their world, being smashed by Imperial forces and left on forsaken planet without any knowledge about events of Horus Heresy and Fall of Caliban had immense impact on beliefs and organization of the new chapter. Penitents believe that what happened to them is punishment for leniency and lack of zeal. Only way of escaping damnation is total and most utter devotion, combined with purification of body and mind by self-mutilation and countless trials. Members of chapter wear ritual robes in color of ash. Some say it signifies humility while others connect it as a reminder of ashes of Caliban or way of honoring twelve apostles sent to human tribes of Styga.