The Ecumene was a peaceful alliance of multiple technologically-advanced spacefaring species, such as the Dakaua, and was well over twenty thousand years old by the time the Hive first encountered it. Member species were known as clients of the Ecumene. Prior to the advent of the Hive, the Ecumene maintained contact with the Ammonite civilization of Fundament and were aware of its destruction, but not of its cause.
The Ecumene was led by the Ecumene Crisis Council during the war against the Hive, which had the authority to marshal the economic and technological resources of all civilizations for the war effort. Its military, the Ecumene Status Army, utilized soldiers or weapons called "war angels". Its level of technology was considerable; Xivu Arath described them as "lords of matter and physical law," and they regularly destroyed entire planets in order to kill Hive leadership.
Ecumene society made use of various synthetic chemicals, possibly specialized pheromones, in communication. Members would "gland" a certain chemical, such as "sixty proof assimilation liquor" or "one hundred twenty proof fight or flight encoding" that would allow them to reinforce the general meaning of a message. Messages were marked with an imperative notice that identified which chemical to gland, as well as what punitive measure would be used ("noncompliance taxation") or what consequence would occur ("certain catastrophic defeat") if the recipient did not comply. Messages were also punctuated with emotional bursts that possibly involved the administration of an additional chemical: "VIGILANCE SPIKE" would likely bring the recipient to a state of increased alertness, while "ENACT IMPULSE" concluded the message and urged the recipient to act on it.
Approximately twenty-four thousand years after the first Hive destroyed the Ammonite civilization and departed Fundament, the Ecumene's frontier fell under attack by the Hive. Over the course of a century, the Ecumene Status Army failed to protect seventeen member worlds from Hive incursions. After the Dakaua discovered the proto-Hive Taox, who explained the Hive's motivations and the identities of its leaders, the Ecumene decided to deploy its most powerful weapons with the goal of completely eradicating the Hive.
This strategy of overwhelming force proved effective for a time, and the Hive's advanced stalled. In response, Oryx acquired the power to Take from the Worm Akka, the power of the Darkness itself, and rapidly regained the advantage. The Ecumene Crisis Council met and determined that the Ecumene and its member species faced extinction within two hundred twenty years, and should therefore devote every aspect of its civilization to fighting the Hive. While this bought the Ecumene some time, the Hive's victory was now inevitable. After a century of war, the Ecumene Crisis Council was killed by Oryx at a place called the Fractal Wreath. Forty years after that, Oryx deceived the Dakaua and eliminated them. The Ecumene fled from the galaxy into the intergalactic void but were pursued by the Hive. One thousand years later, the Ecumene had been annihilated so utterly that only the Hive and Taox, who had managed to flee, remembered it.
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