Delak Krennel was an officer in the Imperial Navy. He was sent to Thrawn's fleet, stationed in the Unknown Regions, because of Krennels brutality and aggression. Discussing, he mocked Thrawns command style by attempting to destroy one of his artworks. Thrawn, however, ordered one of his Noghri Death Commandos to cut off Krennels arm before he could destroy it. This resulted in Krennel receiving a prosthetic limb (which glowed red whenever the use of his muscles was needed). The event gave Krennel a new-found respect and fear for the Grand Admiral.
During the siege of a planet, Krennel decided to pacify it via orbital bombardment. For this act, he was sent to Coruscant to await punishment from Emperor Palpatine himself. However, before Palpatine could do so, he was killed during the Battle of Endor. In the following chaos, he declared himself 'Prince-Admiral' in the following Imperial Civil War.
Despite this, he reluctantly took orders from Imperial Intelligence Director Ysanne Isard, and attempted to capture Leia Organa per her orders, but was forced to abandon his hunt when Imperial-defector Soontir Fel ordered an AT3 Directive (forcing all Imperial forces to cooperate with the codes user). When Imperial leader Sate Pestage escaped New Republic custody, he sought refuge with the 'Prince-Admiral', not knowing of the brutal commanders hatred for him. Delak Krennel killed Pestage and exterminated his entire family, took full control of the Ciutric Hegemony and, once again, became an Independent Warlord.
During the Thrawn Campaign, Krennel offered monetary support and pretended to pay heed to his former Grand Admiral's call for unity. After the Thrawn Campaign, he was targeted by the New Republic to be an example that they did not allow the Warlords to continue. His forces were attacked by Admiral Gial Ackbar and was swiftly defeated. Krennel himself died aboard his flagship when a Concussion Missile hit the Reckonings forward viewport, sending shards through his body.
Delak Krennel gives a Fleet Commander Bonus: the only one, in Era 1, that gives a shield bonus for the Imperial Remnant. The full bonus is 10% health, 10% damage and 5% shield. Combining his Fleet Commander Bonus with an SSD will greatly increase its performance and allows him to easily pull out ahead of a one-on-one confrontation with an MC80b Star Cruiser or Syndic-class Destroyer. Despite being confirmed as an Imperial Warlord in canon, there is no GC scenario that depicts him as part of the Warlord factions and is, thus, only seen in all Era 1 Imperial Remnant GC scenarios exclusively.