Here is the begining storyline for the Lancashire campaign.
For you to fully understand the conflict here is a brief history and culture of Archer IV.
Archer IV lies in the Pale star region of the Maelstorm zone. The planet consist of two large continents a southern currently uninhabited, and an upper northern continent consisting of a conglomerate of hives, windswept plains, and sprawling manufactories producing an assortment of imperial weaponry and equipment.
Unique to Archer IV it is one of a few worlds that have a fully functional STC for building plasma based weaponry this STC is property of the Imperium not the Adeptus Mechanicus a unusual situation. The Adeptus Mechanicus still watch over and administer rights of maintenance to this complex, but that is as far as the relationship goes This STC and its manufactory base has made it a prime exporter of advanced weaponry to the Imperium, it is unknown why the Adeptus Mechanicus has never made a more forceful claim of this STC. Some claims of ancient pacts between the old rulers of Archer IV and the emperor himself when he still walked among men. The ancient tome of the “title of right” a weighty tomb that sits at the governor palace the answer might lie in there but who knows.
Being in the outermost sector of the Pale stars and off the usual warp routes, problems rarely come to Archer IV. Other then the usual tithe fleets that stop by every decade for supply and the occasional Rough Trader stopping for no one comes to Archer IV other then Adeptus Mechanicus explorer teams to investigate the ruins of the southern continent.
The southern continent is uninhabited even though it has a wide range of geography and a biosphere that should support human life all attempts to colonize the continent have failed with one disaster after another falling upon each expedition, because of this it is rumored that the place is haunted the old ruins built by whatever lost civilization just want to be left alone. Over the centuries archeological expeditions have come and gone never finding anything of value until the ending years of the 41st millennium. The last expedition to the ruins went on as usual the only signs of any change when the Adeptus Mechanicus sent a single message to the governor of Archer IV
“The Mechanicus has claimed the continent and all property on it as belonging to the god machine; do not approach, under penalty of destruction.”
Outraged by this theft of land and property governor Argires started to assemble a response to this action but before it could be sent all hell broke loose.
A energy spike tour up into the atmosphere of the planet emanating from the southern continent, destroying the excavation site, a shock wave through the warp, webway, and other dimensions was felt by every pysker individual for a thousand light years. Like a flare in the night Archer IV was on everyone’s radar. Something was waking up on Archer IV and it held the key to great power. When a proper imperial response could be mustered the enemies of the Imperium were on the move soon both sides finally reached the planet and a war for the ruins had begun, what had revealed itself was a fully functional webway gate not of Eldar origin but that of the Old Ones, the builders of the webway the first race to tread the stars by the time the battle was over the enemies of the Imperium had seized the gate and pushing the Imperial survivors to defensive actions on the northern continent
Now with the webway portal in the hands of the enemies of the Imperium, they used the victory to move onto the northern continent, culminating with the capture of the capital city after the incompetent titan legion commander foolishly believed he could win without the sound advice of governor Argires, this disaster in leadership led to the loss of a titan league and fall of the capital city.
Governor Argires is assumed to have survived the fall of the capital and is in hiding with the remains of the planetary defense force. Argires is currently fighting a guerilla war against the occupiers but his forces are depleted and supplies short. If Argires is captured or killed and the “title of right” seized or destroyed there will be no one left to organize a liberation of Archer IV and this world with everything It has will just be forgotten another lost world for the Imperium .