Battle of Dwell
| Shadrak Meduson
Bion Henricos (KIA)
Horus Aximand (WIA)
| 58 Imperial Army Battalions totaling 8 million troops
Small numbers of Iron Hands, White Scars, and Salamanders
Loyalist Mechanicus forces
|Sons of Horus taskforce|
|Nearly all Imperial army destroyed, moderate Astartes losses||Moderate, Horus Aximand wounded|
In the aftermath of the Drop Site Massacre, Iron Hands commander Shadrak Meduson led a series of reprisal raids against the Sons of Horus in revenge for the treachery of Horus. Eventually, Shadrak was even able to marshal together a significant contingent of loyalist troops on Dwell which included 58 Imperial Army battalions, small Salamanders and White Scars assets, and Mechanicum forces. When Horus was able to identify Meduson's base of operations he had his Legion launch an immediate attack.
After brushing aside the Imperial Army troops in a landing assault, the traitor Astartes were shocked to discover hidden Astartes teams throughout the loyalist defensive line on Dwell. During the fight, Sons of Horus commander Horus Aximand was gravely wounded in the face. The Sons of Horus eventually prevailed due to superior numbers of Astartes, but the loyalist forces proved a far tougher nut to crack than they had anticipated.
After the battle Horus met with Fulgrim and Mortarion, and remaining Iron Hands under Shadrak had nearly assassinated the Warmaster with Fire Raptors before escaping. Five days later the traitor forces left Dwell, the planet a smoking ruin.