"Seven armies clashed on this one world, each refusing to back down, each convinced it was in the right."
Kronus was a Tau-controlled world that was featured in Dawn of War: Dark Crusade.
Kronus was originally colonized by the Imperium during the Dark Age of Technology. The first major conflict on the world occurred during the Horus Heresy between the Loyalist forces of the Emprah and Traitor forces of CHAOS. A fucking long time later, the Tau empire somehow managed to wrest control of the planet from the Imperium. Consequently, Tau colonists eventually settled on the world, and the remaining human citizens were placed under Tau rule. The planet would have undoubtedly remained like this had Governor-Militant Lukas Alexander and a regiment of Imperial Guard (plus 5 other races) not come to fuck everything up.
The Dark Crusade
The Dark Crusade was initially started by the Necrons when they decided to start their genocidal campaign against anything unfortunate enough to be living on the planet. However, Farseer Taldeer had already foreseen this awakening and had arrived with her fellow Ulthwé Eldar to try and stop them. General Lucas Alexander arrived next with a regiment of Imperial Guard. He had come in pursuit of Farseer Taldeer, but soon decided to conquer the entire planet for good measure. By this point the the Tau rulers were understandably a little overwhelmed and sent out distress signals calling for help. In response to this, Gorgutz arrived with his armada of Ork ships and sent down asteroids filled with his boyz which then smashed into the planet. Finally, some actual Tau reinforcements arrived lead by commander
rambo Shas'O Kais, who may (or may not) be the Kais from Fire Warrior. Not wanting to miss out on the action, the traitorous forces of Chaos lead by Eliphas The Inheritor decided to show up and start corrupting shit. Lastly, the Blood Ravens lead by Captain Davian Thule finally arrived to capture some presumably sensitive relics dating back to the Horus Heresy (and also purge the entire planet). Because General Lucas didn't want to look like a coward, he refused to back down in the face of the Space Marines' planetary purge. Canonically, the Blood Ravens were the victories of this particular campaign.
|The Planets, Systems, Regions and Sectors of the Galaxy|
|Imperial Homeworlds:||Holy Terra - Sacred Mars|
|Primarch Homeworlds:|| Baal - Barbarus - Caliban - Chemos - Chogoris - Colchis |
Cthonia - Deliverance - Fenris - Inwit - Medusa - Nostramo
Nocturne - Nuceria - Olympia - Prospero - Ultramar
|Planets:|| Armageddon - Cadia - Catachan - Ganymede |
Krieg - Kronus - Sacris - Sanctuary 101 - Scelus
Tanith - Tartarus - Vigilus - Vraks - Zayth
|Daemon Worlds:||Plague Planet - Sortiarius|
|Systems and Regions:||Solar System - Jericho Reach - Kaurava System |
Halo Zone - Stygius Sector - Taelus System
|Types of Worlds:|| Agri-World - Craftworld - Daemon World - Death World - Eldar World |
Forge World - Fortress World - Hive World - Tomb World