Lexicanum wrote:The Howling was an event in 401.M34. Black Templar Space Marines ended the Catelexis Heresy by executing the Cacodominus, an alien cyborg whose formidable psychic presence allowed it to control the populace of 1,300 planetary systems. However, the Cacodominus's death scream echoed and amplified through the Warp, burning out the minds of a billion astropaths and distorting the signal of the Astronomican. Millions upon millions of ships were lost in the resulting upheaval and entire Sub-sectors slid into barbarism without the Adeptus Terra to guide them.

The Nova Terra Interregnum, also known as the "Time of Twin Empires," was a troubled period in Imperial history when the Imperium of Man fractured for a time into warring factions for over 900 standard years during the mid-34th through the late-35th Millennium. During this period, the rebellious Ur-Council of Nova Terra dismissed the authority of the High Lords of Terra and claimed separate rule over the Imperium's Segmentum Pacificus.

After almost a millennium of low-grade civil war and political maneuvering, the Cataclysm of Souls in 975.M35 reunited the Imperium. In that year, the Ecclesiarchy tried to transform the Imperium into a theocracy and usurp the power of the rest of the High Lords of Terra. Their efforts ended only in stirring up massive religious civil wars against the Ur-Council who were denounced as Heretics who stood in defiance of the will of the God-Emperor when they rejected the Ecclesiarchy's attempts to increase its power over the state. This religious rebellion on many worlds of the Segmentum Pacificus ultimately overthrew the Ur-Council and restored the rule of the High Lords over the entirety of the Imperium's territory, though the power of the Ecclesiarchy had been dramatically increased throughout the Imperium as a result.

locarno24 wrote:
Indeed. Don't forget the equally significant sounding Nova Terra Interregnum:

Spoiler:

The Nova Terra Interregnum, also known as the "Time of Twin Empires," was a troubled period in Imperial history when the Imperium of Man fractured for a time into warring factions for over 900 standard years during the mid-34th through the late-35th Millennium. During this period, the rebellious Ur-Council of Nova Terra dismissed the authority of the High Lords of Terra and claimed separate rule over the Imperium's Segmentum Pacificus.

After almost a millennium of low-grade civil war and political maneuvering, the Cataclysm of Souls in 975.M35 reunited the Imperium. In that year, the Ecclesiarchy tried to transform the Imperium into a theocracy and usurp the power of the rest of the High Lords of Terra. Their efforts ended only in stirring up massive religious civil wars against the Ur-Council who were denounced as Heretics who stood in defiance of the will of the God-Emperor when they rejected the Ecclesiarchy's attempts to increase its power over the state. This religious rebellion on many worlds of the Segmentum Pacificus ultimately overthrew the Ur-Council and restored the rule of the High Lords over the entirety of the Imperium's territory, though the power of the Ecclesiarchy had been dramatically increased throughout the Imperium as a result.

I mean, that's one of the five segmenta of the bloody Imperium seceding for 1/10th of recorded history..... to my mind that merits a little more than two paragraphs!

 IllumiNini wrote:
It begs the question if GW and/or FW will ever get around to shedding some more light and/or creating a tabletop scenario around these sorts of major events which are so inadequately explored.