And on the Solar System front:
The Jovian Campaign
The future Steel Legion fought against xenos in the atmosphere of Jupiter itself and suffered extensive casualties in this unforgiving theatre. The experience also revealed serious flaws in the collective psyche and methods of the early Legion.
The Conquest of Cassini
The XIIth Legion, then named the War Heralds, led the battle against the debased and hostile abhumans of the frozen moon, abetted by the Wedal Glaceguard and Angkorian Dragoons. This campaign was also notable as one of the first in which the Void Hoplites of the Satyrnine Ordo fought as part of an Imperial force.
The Battle of Oberon
The Blood Wolves took severe casualties in this campaign, temporarily forcing them to campaign alongside the Juggernauts.
The Apostles of War took a part in the conquest of Pluto.
Eight Legiones Astartes are known to have fought in the campaign to cleanse this mysterious planetoid, known as the "False World." So far this includes the I, II, III, IV, VI, VII, XI and XII.
Edited by bluntblade, 24 April 2020 - 11:26 AM.