The Great Company of Jorin Frostwolf has a might saga, beginning when Jorin Frostwolf took over the Great Company after Finn Goresson, Slayer of Waagh Godstompa and destroyer of Starkrusha. Jorin Frostwolf was Goresson’s Wolf Guard Battle Leader and became an expert ship-to-ship fighter along with the whole of Goresson’s Great Company during the purging of Starkrusha and other ships after that. It was during the boarding of the Alpha Legion Despoiler class battleship Deception Past, that Goresson met his doom in combat with the Alpha Legion Lord Agamemnon. Jorin Frostwolf managed to fight off Agamemnon and set Deception Past to self-destruct. With that deed he succeeded Goresson as the new Wolf Lord in 749.M41.
However, events would see the Frostwolves stranded on the planet Isafold in 752.M41. On Isafold, the Frostwolves quelled a Genestealer Cult uprising after working together with local Planetary Defence Forces of the Astra Militarum, Adeptus Mechanicus, the Legio Rimturs Titan Legion, and Isafold Knightly Houses. After arriving, they were cut off from the rest of the Imperium by massive Warp storms. During this time, the Great Crusade-era Lunar class battleship Frostfang was discovered frozen in the Everfrost glacier. The local Adeptus Mechanicus, were ever eager to examine such a prized archeotech find and assisted the Frostwolves and local archaeologists to excavate the gigantic ship, still mostly frozen in the glacier. As the years and work continued, armouries were thawed and repaired, giving access to previously frozen vehicles and weapons dating from the end of the Horus Heresy. Among the prized finds were a damaged, but functional Stormbird named Sleipner.
As the outbreak of the Genestealer Cult infestation reaches its climax and Hive Fleet Jormungandr made planetfall, the decision was taken to evacuate as much of the surviving population as possible into the almost thawed Frostfang. Fighting a rearguard action, Jorin Frostwolf and his warriors bought time for civilians, Astra Militarum, Adeptus Mechanicus, Titan Legions, and the last of the Isafold Knightly Houses to evacuate. Jorin was grievously wounded in the process, while battling a rampaging Carnifex. As a parting gift, the Adeptus Mechanicus overloaded the massive plasma reactors, setting off a volcanic chain reaction that destroyed all life on the planet. This destroyed all of the Tyranids that had made landfall, and made the now desolate planet uninteresting to the rest of Hive Fleet Jormungandr.
As the stricken Space Wolves orbited the devastated Isafold, the sky split in two when the Cicatrix Maledictum came into being. However, this cataclysm abated the Warp storms that had encircled the Isafold system, and the Space Wolves once again had a stable Warp route back to Fenris. The much decimated Lost Company of Jorin Frostwolf set course for its homeworld, bringing the tens of thousands of surviving Isafold populations with them. They arrived well after the Siege of Fenris and the end of the Indomitus Crusade. Logan Grimnar welcomed the new arrivals, but realised the value a return of a Lost Company meant and kept the Frostwolves hidden from official Imperial records.
The Frostfang was made the official home of the Frostwolves. Most of the civilian population and Adeptus Mechanicus returned to Isafold and established a colony on Isafold’s moon and a network of space stations around the now volcanic planet. But many of Isafold’s civilian population and refugees from the destroyed planets in the Fenris system volunteered to be trained to crew Frostfang. The surviving elements of the Isafold Adeptus Mechanicus, Adeptus Militarum, and Knightly Houses pledged themselves to the Space Wolves. The few remaining original members of the Frostwolves were by now hardened veterans, mostly consisting of Wolf Guard and Long Fangs, with few Grey Hunters surviving and with no Blood Claws.
The problem of the Frostwolves was that they currently do not have a Jarl. Jorin Frostwolf, the curent Jarl, had been badly injured during the evacuation from Isafold. He is in an induced coma, but the Wolf Priests see it as unlikely that he will recover. The Frostwolves’ Wolf Guard, known as the Frostguard, were unsure of how to proceed. The most senior of them had argued whether to inter Jorin into a Dreadnought sarcophagus or not. But so far, the mattar has not been decided, and the Frostwolves are ruled jointly by the three Wolf Guard Battle Leaders of the Frostwolves: Torleif Beasthunter, Fander Quicksilver, and Ingvald Flameheart, until the fate of Jorin would be determined.
The remaining losses were replaced by Terran-born Primaris veterans of the Indomitus Crusade and more recent Fenris-born Primaris recruits. All new Frostwolves choose to pass the Test of Morkai on Fenris, although the veterans performed the rite with considerably more experience than a normal aspirant. With Frostfang being able to act outside official Imperial records, the Great Company was boosted to a strength greater than a normal company with the new Primaris reinforcements.
Grimnar then sent the Frostwolves to help the beleaguered allies to the Space Wolves. Frostfang and the Frostwolves fought during the battle for the Vigilus system, utilising the new Primaris as a vanguard and is now engaged in action tied to the Psychic Awakening around the Virago sub-sector.