Durandal Grohe is an infamous and wealthy Human Rogue Trader. Amassing several continent-sized estates on various worlds of the Imperium, his fleet eventually grew to seven transports as well as the Fast Clipper Durandal's Bliss. After coming across a large trove of Xenos artifacts which he gave to the Adeptus Mechanicus for a tidy sum, he arose the suspicion of the Inquisition but was vouched for by Magos Brunt Carnivrir. After the discovery of the Tau, Grohe made multiple voyages across the Damocles Gulf and engaged in trade with the aliens despite a ban by Imperial authorities. This activity continued, even after the Damocles Gulf Crusade. Nonetheless, Grohe was valued as a source of information on the Tau by certain Imperial officials.
His activity eventually led him into conflict with Inquisitor Ibrahim Matthias, who was certain Grohe was giving the Tau technology used to upgrade their starships. Grohe disappeared soonafter, but several of his fleet craft were discovered and destroyed by the Imperial Navy. Five years later, he appeared at the head of a Tau fleet of thirty ships, guiding them beyond the Farsight Enclaves. The Inquisition and a small Imperial Navy detachment is still pursuing the fleet, but due to the Tyranid threat on the Eastern Fringe only limited resources have been committed and Grohe and his allies continue to evade detection. The purpose of their journey remains unknown.