|Marine||Basic Data||Chapter Symbol|
- ???.M41 - The Avenging Sons Second Company took extremely heavy casualties during the Antillis IV campaign. Outnumbered by the forces of Chaos, led by a warband of the World Eaters, accompanied by the apothecary of the World Eater's first company, Fabrikus, the detachment was ground down and eventually surrounded. Their defences broken, they fought to the end, detonating their position just at the moment of being completely overrun. The only known survivor was a single member of an attached Scout Squad.
- ???.M41 - The Avenging Sons Third Company under Captain Gessart turned renegade after taking heavy casualties against a numberless enemy whilst fighting in the civil war on Helmabad. Deciding that being a renegade band was better than staying and dying for little worth, they led a revolt, killing their Chaplain and those battle brothers who would not follow them. The Third then negotiated with the traitors for safe passage to their Thunderhawk in return for leaving the planetary governor undefended. After fleeing the planet, which was struck by a Warp Storm forewarned by their Librarian, the Third Company painted over their Chapter badges and other Imperial symbols and set course for the Eye of Terror.
- 998.M41 - First Taros Intervention.[2a][Note] A strike force of Avenging Sons fought in the war on Taros. Captain Armaros led the Taros Intervention Force in order to kill Planetary Governor Aulis, but they were surprised by the PDF forces and Tau warriors and failed.[2b]
The Avenging Sons wear navy blue power armour with yellow trim on their shoulder armour and their symbol is a white cross. A white diagonal stripe with a roman numeral in the centre denotes the company.
- Armaros - Captain. Commander of the Taros Intervention Force, during the First Taros Intervention (Taros Campaign)[2d]
- Gessart - Captain, Third Company. Went renegade.
- Einem - Veteran Sergeant. Took part in the First Taros Intervention.[2e]
- Foras - Veteran Sergeant, 1st Company. Took part in the First Taros Intervention.[2f]
- Andura - Sergeant. Took part in the First Taros Intervention as a leader of third Tactical squad. Was killed by Tau during the first phase of operation.[2g]
- Actium - Apothecary. Took part in the First Taros Intervention.[2h]
- Korpus - Apothecary, 2nd Company. Took part in the Antillis IV Campaign.[Needs Citation]
- Baraqel - Chaplain. Took part in the First Taros Intervention.[2e]
- Gathein - Primaris Epistolary. Member of Tetrarch Decimus Felix's Honour Guard, the Chosen of Vespator.
- Hakael - Dreadnought.[2c]
- Rykhel - Battle-Brother, Third Company. Last known surviving loyalist of the Company after Captain Gessart went renegade.
Per the Dark Imperium novel by Guy Haley, a Chapter of Primaris Space Marines is founded at the Pit of Raukos as the last stage of the Ultima Founding, called the Avenging Sons. Guilliman bases this new Chapter at Callimachus, within the reformed Ultramar.
- Note: Although on page 19 of Imperial Armour Volume Three - The Taros Campaign is not explicitly stated that the First Taros Intervention happened in 998.M41, the Taros Campaign itself was in 998.M41 and as the First Taros Intervention was part of this conflict, so presumably it happened in the same year.
- 1: Apothecary's Honour (Short Story)
- 2: Imperial Armour Volume Three - The Taros Campaign
- 3: Renegades (Short Story) - Heroes of the Space Marines (Anthology), pg. 86
- 4: Imperial Armour Volume Two - Second Edition, pgs. 8-9
- 5: Dark Imperium (Novel), Chapter 20
- 6: Insignium Astartes, pg. 60 - Image of the Avenging Sons' Space Marine
- 7: Belisarius Cawl: The Great Work (Novel), Chapter 5
- 8: The Rewards of Tolerance (Short Story)
- GW Space Marines Gallery (accessed 2007.02.18) (Image)