Battle of Palantia
From Gineipaedia, the Legend of Galactic Heroes wiki
In 751 UC (442 IC / 3551 CE), Alliance Admiral John Drinker Cope led an Alliance fleet into battle against the Galactic Empire in the Palantia Starzone but performed uncharacteristically poorly. The battle was horribly one-sided, resulting in massive losses for Cope's fleet: there were over 300,000 casualties. After less than 4 hours of combat, Cope's fleet had been obliterated and the Imperial forces had begun to withdraw from the starzone: John Drinker Cope himself was killed in the combat.
Arriving at the starzone after the battle's end, Alliance Admiral and fellow Year 730 Mafia member Frederick Jasper pursued the withdrawing Imperial forces, hoping to dole out vengeance for his fallen friend, Cope. Attacking from behind, Jasper inflicted casualties on the enemy and was able to exact a small measure of vengeance. (SL: 'Between the Mourning Dress and Military Uniform')
After the battle, rumours began to circulate throughout Alliance territory that Admiral Jasper had had the opportunity to reinforce Cope's fleet much sooner, but had deliberately delayed in order to monopolize the battlefield glory for himself. In her grief, Cope's widow publicly denounced Jasper, blaming him for her husband's death, but later recanted. (SL: 'Between the Mourning Dress and Military Uniform')