Raised in what became known as the Ultima Founding, the Primaris Marines were deployed across the galaxy during the Indomitus Crusade by Guilliman and Cawl after the opening of the Great Rift.

It was only thanks to the Sangprimus Portum - a device that held potent genetic material originally harvested from the primarchs themselves - that Archmagos Cawl was able to create these biotechnical miracles. These organs enhance their physiology to an even greater degree than the Firstborn, making them yet stronger and tougher.

Primaris Astartes are also implanted with 22 rather than 19 gene-seed organs, and their gene-seed is more resistant to mutation than that of their predecessors. However, Primaris Space Marines are bigger - standing nearly 10 feet tall in their armour in some cases - more resilient, physically more powerful and possess faster reaction times than their original Astartes counterparts, now often referred to as the ' Firstborn.' Their creation was initiated on Mars on the order of Primarch Roboute Guilliman in the days immediately after the Second Founding in the early 31st Millennium.Ĭawl used the genetic template of the original Space Marines created by the Emperor for His Great Crusade as the starting point for the development of these new Astartes. The Primaris Space Marines are a new breed of transhuman warriors developed across the span of ten thousand standard years by Archmagos Dominus Belisarius Cawl. Primaris Space Marine Intercessor of the Ultramarines Chapter in Mark X Tacticus Power Armour wielding a Mark II Cawl Pattern Bolt Rifle. Ultramarines Primarch Roboute Guilliman, Lord Commander of the Imperium

' They were forged for Mankind's darkest hour - and that hour is upon us.'

Space marines vs imperial guard