Exterminator War

The Attacks

Out of nowhere, colonies on Quadrants 5, 6 and 7 came under attack. In late 3196 and early 3197, some 27 years or more ago, colonies in the 'eastern' Quadrants - Quadrants 5, 6 and 7, suddenly began going quiet. Merchant ships visiting them reported that the colonies had been destroyed, apparently by orbital bombardment. Initially these were far-flung, small, mainly independent worlds, and the alarm did not really become raised until the colonies of major powers were hit by huge alien robot battleships of unknown type. Hastily assembled colonial fleets tried to defend against these in piecemeal fashion and were overwhelmed. Many major power colonies, including some quite large and wealthy ones, were destroyed with machine-like precision and efficiency.
Over the course of just two years from their first appearance, the 'Exterminators', as they were dubbed, destroyed 76 human worlds and damaged several others: 11 Esteeler, 5 Martian, 4 Earther, 2 Xyonist (including the colonial capital world Dubai in Quadrant 7), 2 Venerian, 1 Sirian, and over 50 independents. Human casualties were in excess of 900 million souls, nearly 300 million of them Xyonists.

The Response

Against such an existential threat, local forces began banding together, and then central governments began reaching out to create something unprecedented - a pan-human alliance which was eventually formalised in the 3200 Treaty of Old London (Earth). By then, reinforcements from the Core Worlds, combined fleet actions and a rapid evolution of new tactics to deal with the huge alien Exterminator 'super-battleships' (ESBs) had led to the defeat of most major Exterminator fleets and the location and destruction by mass driving of their bases, which were mainly on depopulated human worlds. A final, conclusive engagement was fought at Tuskan in late 3200, destroying 14 ESBs and capturing another two. The remaining ESBs had by then broken up into raiding pairs of 'Viking' modules, some of which struck into Quadrant 0, even causing casualties on the Esteeler core worlds of Asteel and Disney World before they were hunted down and destroyed. The last known contact was in 3201.

Origins

No communication with the Exterminators had ever succeeded, and so while effort went into rebuilding and years of peace passed, humanity bent its efforts to the study of captured Exterminator 'brains' (artificial intelligences of a fairly limited kind) to work out where they had come from and why they wanted to eradicate humanity. Eventually analysis of captured brain units produced an internal 'map' they had used which was believed to correspond to a pre-human civilisation, the Forerunners. It appeared that the hypothesised Hostile Exterminator Builders (HEBs) which had sent the Exterminators were enemies of the Forerunners, or possibly according to one intelligence report a rogue offshoot of Forerunner civilisation.

The location of the HEB homeworld was encoded in the brains - 5 years travel away at hyperspace speeds - and talk turned to a retaliatory strike, but the years of peace had allowed old rivalries and mistrust between the major powers to resurface, and the distance seemed to preclude military operations. As an interim measure, Earth sent a long range scouting force to examine the HEB worlds, while Wolf and the Venerians set up military colonies that were to act as forward bases for any future action against the HEBs.

Summary

- The Exterminator Super Battleships (ESB) were wholly automated and whilst possessing a high degree of artificial intelligence, they were not sentient.

- The Exterminator Super Battleships were built by an civilisation located some 5 years travel time away from human space. These became known as the 'Hostile Exterminator Builders' or HEBs.

- This HEB civilisation has some connection with The Forerunners, possibly it has been influenced by an escaped Forerunner AI Warship that failed to be deactivated after an ancient war.

- The Exterminators had come looking for The Forerunners, and were trying to provoke a defensive reaction from them.