The Age of Strife, also sometimes referred to as Old Night in older Imperial histories, is the name for the chaotic and highly fragmented period of human history that began in the 25th Millennium A.D. and ended in the 30th Millennium. According to the “official” histories of the Imperium, the precise details and dates of the Age of Strife are not known. This is due to the data having been lost over vast amounts of time, the sheer chaos of the period, and censorship by various Imperial authorities who seek to prevent the people of the Imperium from learning more about the rampant uncontrolled psykers and daemonic Chaos incursions that marked many of the human worlds of the period. It was in reaction to the terrible tragedies and loss of life that befell Mankind during the Age of Strife that the Emperor of Mankind first decided to unite all of humanity beneath His enlightened rule, beginning the Age of the Imperium.

The Empress discovering the primarchs of the 1st and 3rd legions in her conquest of Manehattan.