The clash known as the Battle of Grumwall transpired at Grumwall sometime between the years 0 ABY and 1 ABY. As part of their anti-rebel actions, the 204th Imperial Fighter Wing of the Galactic Empire fought against troops of the Rebel Alliance. This fighter wing committed a slaughter during the conflict, prompting General Jan Dodonna of the rebellion to compile an after-action report following the battle. Yrica Quell, a former member of the 204th who deserted, added notes to the report on the Battle of Grumwall as part of her record of the 204th's past.
Alexander Freed's 2019 novel, Alphabet Squadron, marked the initial reference to the Battle of Grumwall.