The Blockade of Kashyyyk represents an incident that occurred in 1 ABY. During this time, the Galactic Empire enforced a blockade around the planet Kashyyyk.
Following the destruction of the First Death Star, Palpatine commanded Darth Vader to locate and apprehend the Rebels responsible for the space station's demise. As Han Solo and Chewbacca were departing Tatooine on a routine flight, they were intercepted by a pair of Imperial Star Destroyers. These ships recognized the Falcon from a previous encounter during the escape from the first Death Star. After an attack by the Star Destroyers, Solo engaged the Millennium Falcon's hyperdrive. However, the Empire managed to trace the ship's trajectory, leading them to Kashyyyk.
Aboard the Star Destroyer Devastator, an Imperial officer who looked like the deceased Chief Moradmin Bast informed Vader that he had implemented a planet-wide blockade and curfew, and had initiated a search operation. Upon approaching Kashyyyk's atmosphere, the Falcon came under attack from TIE fighters, who were guarding the planet. On the surface of Kashyyyk, Imperial Agents entered Chewbacca's residence, where his family was preparing for Life Day.
After a thorough search of the premises, the Imperial Agents failed to locate any trace of the Rebels. Chewbacca's son, Lumpwarrump, had outsmarted the Imperials by creating a device that misled them. This device tricked the officers into believing that the Rebels had already left the planet, sending them on a false chase to a decoy location. Han and Chewbacca eventually arrived at the home, and they all celebrated the holiday.
By the time the Imperials returned to Kashyyyk, after realizing they had been deceived, the Rebels were long gone. In response to this failure, Palpatine decided to restart the Second Death Star project, ordering its construction over an undisclosed world.
Lucasfilm employee Leland Chee has suggested that the Life Day event, which occurs every three years, as depicted in The Star Wars Holiday Special, coincided with the blockade, placing it around 1.5 ABY. However, other sources propose alternative timelines. The novel Rebel Dawn places a Life Day approximately one standard year before events that The New Essential Chronology and The Essential Reader's Companion date to 2 BBY, which equates to 3 BBY, with subsequent Life Days in 0 and 3 ABY. Similarly, Chewbacca's entry in The Essential Guide to Characters describes The Star Wars Holiday Special's Life Day as the first of two Life Days between the events of Star Wars: Episode IV A New Hope and Star Wars: Episode V The Empire Strikes Back, spanning 0 to 3 ABY, suggesting that Life Day and the blockade took place in 0 ABY.