War for Archos

The War for Archos was a joint-Imperial castigation campaigns conducted by the Corrosive Thorns Space Marine Chapter and two regiments of the elite Tempestus Scions against the vile Alpha Legion when they invaded the vital Adeptus Mechanicus forge world of Archos in the latter centuries of M37.

History
In the latter centuries of M37, the Forge World of Archos came under attack by the forces of the treacherous Alpha Legion who sought to take over the vitally important mechanicus-held world in order to produce more gear for their legion. The Corrosive Thorns rapidly responded to the threat, aided by two elite Tempestus Scions regiments to help defend the world from the threat. When the first three waves of the Forces of Chaos hit the Imperial defenders, they managed to dispatch them, but when the fourth wave arrived it brought a large amount of daemonic engines which would force the defenders to back down. The attackers took more ground. Only after managing to take down the daemon engines could the Imperial defenders take back the ground lost. The Defenders would push the attackers off-world but not without losing 25% of the planet's vital manufactorums.