The Tempered Souls are a partially compliant-Codex Astartes Chapter created during the 14th Founding from unknown genetic lineage. This Founding was just one of many multiple Foundings of Adeptus Astartes Chapters, which occurred between 975-991.M35, a tumultuous period in Imperial history. During the latter decades of this millennium, the Imperium was rife with civil disobedience, wars, invasions and various disasters. The troubled period known as the "Time of the Twin Empires" was coming to end - a fractured time when the Imperium of Man was split into two separate warring factions for nearly 900 hundred years. During this period, the rebellious Ur-Council of Nova Terra dismissed the authority of the High Lords of Terra and had claimed separate rule over the Imperium's Segmentum Pacificu