The invasion began when Kraghoor sent a wave of Cursed Thrall to cause havoc among the Tai worlds, destroying Taishibethi orbitals, star-webs, and other infrastructure. The Taishibethi military, composed of battleplates and arsenal ships, retaliated and fought the Hive vanguard. The Warpriest entered the conflict next and defeated them, opening the way to the Tai heartland.
Mengoor and Cra'adug distinguished themselves at this time by going to a place called the Raven's Bridge, the seat or palace of the Emperor Raven, and spent the next decade warring with Tai soldiers. Eventually the Emperor Raven herself appeared and defeated them, destroying their war moon with a single swipe of her claws.
Oryx, however, was waiting and with his power he Took the Emperor before she could react, and transformed her into the Perfect Raven. From then on the Taishibethi morale waned and they were swiftly defeated. The Hive's religious text describes it as "[n]ever again [was] a Taishibethi child born". In their defeat they wailed against Oryx, asking why he fought them, contrasting their peaceful ways with his war, and he answered that only the will to exist, and to fight for it, is all that mattered.