The Kashyyyk Massacre, also known as the Kashyyyk Death March or the Black Forest Massacre, was a highly-publicized atrocity committed by the Galactic Empire that occurred in Year 6 on Kashyyyk. The massacre was perpetrated by Task Force Delta Executive Officer Tnsumi Shine of the Galactic Empire under the command of Admiral Adar Machkhit. Every year, an official day of remembrance — entitled "Black Forest Day" — occurs on Days 356-357. The purpose of the annual event is to remember the countless Wookies and other sentient beings who perished during the Kashyyyk Massacre.
Emperor Vodo Bonias of the Galactic Empire was renowned for his hatred of Wookiees, and he allegedly began planning the massacre of the Wookiee population on Kashyyyk in early Year 5. The operation was later described by Imperial officer Joshua Chamberlain as "a clean-up involving the Wookiee population of the planet." Allegedly, circa Year 6 Day 356, Imperial soldiers formed a human chain that swept across settled districts in an attempt to corral the Wookiees. Although Wookiees were their primary target, Imperial forces ultimately arrested and executed a large variety of sentient beings on Kashyyyk. Task Force Delta forces made extensive use of AT-AT walkers and drop ships transports for this brutal campaign of arrests and executions.
Following public outrage against the massacre, the Galactic Empire claimed that Task Force Delta was deployed on the planet to investigate whether the Wookiee inhabitants were conspiring with the Tenloss Syndicate and the New Anzat Order to overthrow Imperial rule. After they claimed their suspicions were confirmed, they ordered to execute every individual on the planet's surface for "collaboration with the enemy" without a trial and without even confirming their identities.
On the same day, in Year 11, the New Republican Wookiees were fighting once more against the Empire, in the Battle of Sacorria.