Battle of Rust
The Orks of the 'Krooked-Klaw' Empire of Wardog Kulo held onto a territory of more than sixty inhabited star systems in the galactic northeast. Rust itself had been made into a slave mining colony comprising millions of Orks and a vast population of abused human slaves. It was designated by the Emperor as one of the primary targets of the Crusade, and eleven entire Space Marine Legions and hundreds of Imperial Army groups were mobilized for the operation, known as the Seraphina Offensive.
While the Offensive itself targeted the entire Krooked Klaw Empire, it fell to the X Legion (later known as the Iron Hands) to liberate the strategic world of Rust. They were supported by two battle groups of the Urshan Velites Imperial Army and the Halgentine Covenant of the Legio Cybernetica. The effort was to be led by Lord Commander Amadeus DuCaine.
DuCaine formulated a plan of attack which owed much to the Hammer and Storm tactic of Albia. After forcing an orbital landing, DuCaine ordered the Urshan soldiers to make planetfall in full strength. He had them form up in a triangular deployment zone between the three largest Ork settlements. In this they successfully 'raised the storm'; the Orks bestirred in their millions by the attack from the above. Within hours of the battle a bloodbath had erupted, and DuCaine did not allow the embattled Urshan Velites to retreat or receive reinforcements. It was then that DuCaine deployed the X Legion, landing by gunship and assault landers to blast through the Orks. The Astartes landed with Malcador and Land Raider tanks along with Dreadnoughts. Moving forward as a single slow-moving mass, the Legion destroyed everything in its path with its massed firepower.
The X Legion beat off several reckless Ork counter-attacks until the Greenskins ran out of bodies and machines. The X Legion itself had only taken less than a fifth of its number in fatalaties, far lower than the earlier projections.