Plo Koon was a Kel Dor Jedi Master who served as a member of the Jedi High Council during the last years of the Galactic Republic. He served as a respected Jedi General during the Clone Wars, a pan-galactic conflict between the Republic and its splinter state, the Confederacy of Independent Systems. During the war he frequently undertook dangerous missions with the soldiers under his command, the 104th Battalion.
Koon was a survivor of the First Battle of Geonosis, the opening salvo of the Clone Wars that claimed the lives of nearly 200 Jedi. Early in the war he embarked on a mission to track down the Separatist warship Malevolence. Following several attempts to destroy the weapon, Koon and several of his peers managed to take it down. Among the Jedi he often worked with was Ahsoka Tano, whom he had discovered years before the war and shared a special bond with. During the war he played vital roles in the First and Second battles of Felucia, the Battle of Lola Sayu, and the Battle of Kadavo. As the conflict thickened, Ahsoka was framed for a terrorist attack on the Jedi Temple and was subsequently removed from the Jedi Order. When the true culprit was discovered, Koon and the Council offered her a chance to rejoin, but she refused and left the Jedi.
In the late stages of the Clone Wars, Koon led the 442nd Siege Battalion in the Battle of Cato Neimoidia. As he and a squadron of ARC-170 starfighters flew over the bridge cities following their victory, he was shot down and executed by his troops during the issuance of Order 66, during which the Jedi were massacred across the galaxy by their soldiers.