Brother-Captain Thule is set to be the leader of the Space Marine deployment to Kronus in Dark Crusade. When he arrived on the planet, he sent a message to Governor-Militant Alexander to evacuate all civilians and Imperial Guardsmen before the Space Marines could begin their purge. However, Alexander refused, and now the Marines must fight other soldiers of the Imperium. Thule regrets having to kill his brothers-in-arms, but orders are orders - Kronus must be purged. At this time, not much is known of him other than being part of the Blood Ravens. Thule is armed with a standard-issue Chainsword and Bolt Pistol at the beginning of the campaign, and when fully upgraded carries a daemonhammer and melta-gun, along with wearing heavily ornate artificier armour, and a backpack-mounted teleporter.
When the Blood Ravens finish off the other seven races in Dark Crusade, they collect their spoils of war and preserve some of the Chapters' secrets on the planet. The Inquisition arrives to question their actions but the commanding officers manage to finagle their way through the interrogations by claiming they were just following orders from their Chapter Master. The narrator then states that the darkest time for the Chapter begins after they complete their Dark Crusade. The survivors of the shattered 1st Kronus Regiment bear a deep hatred for the Blood Ravens even though Thule arranges safe transport for the Guardsmen who actually fought against his Marines, and executes every one of the rebelling 1st Kronus 5th Company soldiers.