Kieldar is an Imperial Fortress World that lies near the Cadian System and the Dinorwyc Cluster. It rebelled against the Imperium, and the Astra Militarum was mobilised to put down the uprising in what became known as the Kieldar Offensive.
Those deemed a threat to the new order on the world -- representatives of the Ecclesiarchy and military advisors from Cadia -- were executed shortly afterwards. A Cadian Astropath warned the wider Imperium of the rebellion before the executions.
Fearing that the uprising would spread to the strategically vital Agri-worlds of the Dinorwyc Cluster, the Astra Militarum was ordered by Segmentum Command to assemble a task force to assault Kieldar.
The result was the Kieldar Offensive which led to the overthrow of the rebellion and the ultimate return of Kieldar to Imperial rule.
Kielder possesses several continents, with the northern one considered the best place to establish a drop site by the Astra Militarum and Imperial Navy.
One of the fortifications on Kieldar is Darkridge Hold. During the Kieldar Offensive, the Astra Militarum besieged it for 33 solar days using Basilisk artillery bombardment and a company of super-heavy tanks consisting of at least one Baneblade. Darkridge's main line of retreat was towards the Krokorax bastion near outlying cities and trenchlines.
During the offensive, Taskforces Ironwind and Steel Hammer first besieged these cities in an attempt to prevent the Kieldarian rebels from reinforcing Darkridge, and then advanced through them to cut off the rebels' lines of retreat. Kieldar returned to Imperial control shortly afterwards.
- Warhammer 40,000: Rulebook (5th Edition), pp. 142-143