Long ago, during the turbulent era known as the Age of Strife, Warp travel became impossible and all the worlds which humanity had claimed were cut off from one another, forced to fend for themselves without the support of their neighbours in other star systems. Following the end of Old Night the Emperor of Mankind first publicly revealed himself during a series of conflicts to reunite the disparate techno-barbarian nations of Terra, collectively known as the Unification Wars. Following their successful conclusion the Emperor began to forge the foundation of the Imperium of Man in the 30th Millennium. The Emperor began a massive scientific effort to create the Primarchs -- 20 genetically-engineered sons that would serve as the Emperor's generals and command the Emperor's forces during the