Sons of Antaeus

A Loyalist Space Marines Chapter of unknown origin created during the Cursed 21st Founding, the Sons of Antaeus have long led a mysterious existence. It is unknown what exactly went wrong, if anything, during the creation of these mysterious Space Marines and what mutant flaws they may possess within their gene-seed. As with many other Space Marine Chapters, the Sons of Antaeus are inspired by the cultural aspects of certain ancient Terran societies, in this case the ancient Greek mythological figure of Antaeus, an incredibly strong and near invincible man descended from the god of the sea Poseidon and the Titaness Gaia, Mother Earth herself. As long as Antaeus' feet touched the ground, his connection to the Earth granted him great strength and invincibility. But Antaeus was killed in a wrestling match with the ancient Greek hero Heracles when he realized that by holding the giant in the air, Antaeus became as weak as other men. Like Antaeus, the Astartes of the Sons of Antaeus Chapter are unusually large and robust physical specimens, even among their kind, and they are capable of surviving wounds and physical injuries that would kill even other Space Marines. The obvious links between the Chapter's name and Herculean mythology could hint at a link between the Sons of Antaeus and the Ultramarines Chapter, but there is no official evidence to back this assumption. The Sons of Antaeus' unusual physical abilities may be the result of the mutation in the Chapter's gene-seed that has affected so many other Chapters created by the Imperium during the 21st Founding. There are many rumours as to why they are so difficult to destroy, ranging from reinforced skeletons to enhanced genetics. At this time, the truth remains unknown. 

Part of the Cursed 21st Founding, the Sons of Antaeus have a mysterious existence. It is unknown what exactly went wrong, if anything, in the creation of these mysterious Space Marines.
The only official Imperial record that lists the Sons of Antaeus is the Chronicals of the Third Inter-Guild War of the Inca Sector 850-901.M41. Captain Rakman of the Subjugators chapter reported that the Sons of Antaeus showed up unexpectedly and opened a 2nd front forcing the Eldar pirates to attempt to redeploy. This resulted in the destruction of the Eldar raiding force.¹
It is reported that they have been seen in action by other reputable Imperial forces. There are many conflicting stories, but two things remain constant.
The Sons of Antaeus' livery is grey and black, and they are capable of withstanding damage that would kill any normal Space Marine in seconds. There are many rumors as to why they are so difficult to destroy, ranging from reinforced skeletons to ancient genetics. At this time, the truth is not known.