Kashyyyk/Legends

Kashyyyk was the home planet of the Wookiees. It had four continents and was mostly covered in lush, tree-filled forest, although it did have a small amount of desert region in the rain shadow of its small mountain ranges. Its prevalent ecology could be politely described as a "layered deathtrap": the planet's surface was covered with wroshyr trees several kilometers high and the dangers presented by local wildlife increased as one descended toward the forest floor.

According to Wookiee culture, this vertical environment consisted of seven levels. The bulk of Wookiee civilization was located on the uppermost seventh level, and even the bravest Wookiees rarely ventured below the fourth level. The ground level was known as the Shadowlands.

Besides the primary sentient Wookiees, Kashyyyk was home to a host of other animal species including kroyies, can-cells, katarns, kkekkrrg rros, webweavers, netcasters, flame beetles, gorryl slugs, sureggi, and various species of banthas.

History
In the millennia before the rise of the Galactic Republic, Kashyyyk was a member world of the Infinite Empire. Its surface was terraformed by the Rakata for agricultural purposes, but the collapse of their empire left the machines unattended, resulting in the abnormally large foliage.

Later, it was discovered by Czerka Corporation, which termed the planet first G5-623 and then, after a poll of stockholders, Edean. Czerka control of 'Edean' was disrupted when, in 3,956 BBY, the enslaved Wookiee populace overthrew the local corporate headquarters and drove all outsiders off the planet. It was presumably some time after this before Kashyyyk decided to join the Old Republic.

The Wookiees were welcomed into the Republic through dealings with the Corellians and Alderaanians. Eventually, Kashyyyk was even represented in the Galactic Senate, with Senator Yarua being the last Kashyyyk representative prior to the outbreak of the Clone Wars.

During the Clone Wars, the Confederacy of Independent Systems invaded Kashyyyk. Conquering the planet would prove an asset since it would enable the Separatists to control hyperspace route planning and use the Wookie's secret routes to disrupt galactic trade and communication. In response, the Republic dispatched a task force led by Master Yoda to defend Kashyyyk. There, a combined force of Clone troopers and Wookies repulsed the Separatist droid invaders at the Battle of Kashyyyk.

However, victory was short-lived. With the rise of the Galactic Empire, the Jedi were branded enemies of the Republic. The Clone troopers then took over the planet and placed it under martial law. In response, the Wookies rebelled against their new oppressors.

At the advice of the Trandoshans, the Empire enslaved the Wookiees for their strength. Wookie captives were used for countless Imperial projects including the Maw Installation and the Death Stars. However, because of their devotion to their homeworld, many Wookies would evade the Imperial garrison to revisit their beloved forests for important Wookie holidays.

After the Battle of Endor, the Wookiees were liberated from slavery by the Alliance of Free Planets. The Nagai also attempted to enslave the species though they were repulsed by the New Republic. Kashyyyk was represented in the New Republic Senate by Kerrithrarr and the planet became key signatory and member world of the Inner Council. The planet also welcomed trade and its city of Thikkiiana became a major exporter of computer technology.

Behind the Scenes
The original drafts of Return of the Jedi called for the Death Star II to be built in orbit around Kashyyyk by Wookiee slave labor. It wasn't until later drafts that the setting and characters were changed to the forest moon of Endor and Ewoks.