Damocles Gulf Crusade - Operation Hydra: Their advance halted, the Imperial forces, commanded in this operation by General Wendall Gauge of the Astra Militarum, had to dig in to avoid the worst of the T'au firepower. The T'au possessed superior night-fighting capabilities which they exploited, moving up to extreme range and opening fire, only to withdraw at dawn. Space Marine combat patrols with their genetically-enhanced senses helped to stem this problem, but the Imperial losses continued to mount.This was compounded by the constant worry of the crusade's officers that a new T'au fleet would arrive; the crusade fleet was badly damaged and could barely protect its troop transports, let alone provide air cover for the ground forces on Dal'yth. As the siege wore on, more T'au arrived at the front from elsewhere in the world each local day.General Gauge concluded that the crusade had stumbled onto a major T'au population center within their empire and that his resources were insufficient for the task before him. Plentiful reinforcements had been promised at the outset of the crusade but none had arrived. Inquisitor Grand of the Ordo Xenos was all for evacuation of the world followed by an Exterminatus order, as the T'au were clearly too dangerous a species to be allowed to continue to exist.Yet the Imperials had found the T'au to be honourable adversaries and there was marked opposition to such an extreme course of action within the crusade's high command, especially from the Astartes. While the crusade's council of war was paralysed by this internal debate, General Gauge acted.He formed his Titans up with the Brimlock Regiments and attempted to force the river line of defence down the right flank, trapping the T'au against the sea. As preparation his artillery pounded other sectors of the front and Imperial Navy fighters began an offensive against T'au airfields that was costly to the Imperial pilots but kept T'au aircraft from the front.The Imperial strike force took their primary objective in the first few solar hours of the offensive -- a town containing a bridge across the river to Gel'bryn -- and achieved complete tactical surprise. As the assault continued, it was countered by ultra-mobile T'au units deployed from the ubiquitous Manta missile destroyers.For the rest of the local day, a running battle was fought through the Dal'yth suburbs that ended with the Imperium's troops a mere five kilometres away from trapping tens of thousands of T'au between the city and the sea. Overnight, the T'au troops disengaged and fell back to a new defensive line beyond Gel'bryn.By the morning the T'au were gone and while the city itself was infested with lurking Kroot, the starport on the outskirts of Gel'bryn was quickly secured by Imperial troops.The starport, combined with the distance from the city which the T'au defenders had retreated, provided an excellent opportunity for the successful evacuation of Imperial forces from Dal'yth Prime, and General Gauge took it.Resistance from the Inquisition and Adeptus Astartes to this course of action was overruled by the arrival of an express astropathic order in late 745.M41 from Inquisitor Fidus Kryptman to return to Brimlock with all available forces as quickly as possible.The T'au sensibly realised that getting in the way of the Imperial evacuation would serve no sane purpose and parleys held under flags of truce were honoured by both sides. The first seeds of cooperation between the Imperium and the T'au Empire were sown, though these would take time to bloom in the aftermath of such a brutal conflict.In the course of the Damocles Gulf Crusade the Imperium had learned to respect the T'au skills of war and the T'au had discovered the true scale and bitterness of a galaxy they had previously thought to just be theirs for the taking.The message from Inquisitor Kryptman had informed the crusade command of the first Tyranid attacks upon the Imperium and within the Segmentum Command all hope of a quick victory over the T'au had already faded. It is conceivable that the T'au might have blockaded the crusade and trapped its remaining forces on Dal'yth Prime, but as an enlightened species, the T'au saw more advantage at that time in opening a diplomatic dialogue with the Imperium.The crusade forces were allowed to withdraw back into Imperial space unmolested, allowing the Fire Caste to swiftly reclaim those T'au Sept worlds it had lost to the Imperium's offensive at the outset of the conflict.But the Damocles Gulf Crusade simply marked the start of over two hundred standard years of brutal warfare between the Imperium of Man and a T'au Empire determined to spread the Greater Good across the galaxy.