The Jedi are central to Star Wars, and in the final years of the Republic their importance grew when they began serving as generals in the Clone Wars. The Order itself was led by the Jedi High Council, twelve senior Jedi which included the Jedi Grandmaster. These twelve oversaw the appointment of Jedi to important missions, and became increasingly political during the conflict.
The Clone Wars took their toll on the Jedi Order, and Council seats changed hands throughout the conflict. Several serving members were killed in the war, including Master Even Piell, while others fell during Order 66 and the Jedi Purge, with great Jedi such as Plo Koon and Depa Billaba dying in this way.
Kit Fisto
The Nautolan Jedi Master was one of the foremost generals during the war, being particularly prominent in the Invasion of Mon Cala, and his conduct would earn him a seat on the Council. He was more laid back than many Jedi, always ready to laugh even in desperate situations.
A skilled lightsaber duelist, Kit Fisto once fought General Grievous, confronting the cyborg in his personal fortress. Mace Windu selected him to help arrest the Chancellor, and he was able to deflect several of the Sith lord's attacks before being struck down.
Anakin Skywalker
As the Chosen One, Anakin was perhaps the most important member of both Jedi and Sith Orders. He served with distinction in the Clone Wars, though his unconventional nature could exasperate more careful Jedi. His appointment to the Council was at Palpatine's request, with the Chancellor naming him as his 'personal representative'.
Despite being one of the youngest Council members ever, Anakin was outraged that he wasn't given the rank of Master as well. His time on the Council would be short-lived, though, as not long after he would be responsible for the fall of the Order, carrying out the Great Jedi Purge as Palpatine's apprentice.
Even Piell
A dour, no-nonsense Jedi with a unique sense of humor, Even Piell was a skilled warrior with a fierce reputation, and had lost his left eye at some point in his younger life. While serving on the Council during the Clone Wars, he was captured by the Separatists while carrying information about secret hyperspace routes.
Held in The Citadel, a prison specifically designed to contain Jedi, Master Piell was rescued by a strike team including Anakin, Obi Wan, and Ahsoka. While escaping across the planet's surface, Piell was attacked by a pack of Anoobas sent to track the escapees down, and managed to pass the secret information on to Ahsoka before dying of his wounds.
Shaak Ti
During the Clone Wars, Shaak Ti spent most of her time on Kamino, overseeing the creation and training of new clones for the Republic. She was integral to the defense of the cloning facilities during the Separatist's invasion of the planet.
Shaak Ti almost uncovered the secret behind the clones' inhibitor chips. After Tup's chip malfunctioned, and he killed his Jedi commander, Master Ti oversaw the investigation of the incident. Unfortunately, she wasn't able to gain clone trooper Fives' trust, and his discovery about the true use for the chips was lost when he was killed, allowing Order 66 to proceed as planned.
Ki-Adi-Mundi
Ki-Adi-Mundi was one of the few Jedi admitted to the council when still a Jedi Knight. He was considered highly intelligent, with a binary brain that could solve complex problems easily, but also had a tendency towards arrogance, like many Jedi at the time.
His race of Ceraens were rare, and Mundi was permitted to have a family and children to help keep their population stable. Despite his wisdom and skill as a Jedi, he didn't believe Dooku was responsible for the attack on Senator Amidala, and also quickly turned against Ahsoka when she was accused of bombing the Jedi Temple.
Depa Billaba
The Padawan of Mace Windu, Depa Billaba was a skilled Jedi, and an expert in Form III lightsaber combat. She served in the Clone Wars and was badly injured in battle on Haruun Kal, spending months in recovery and being temporarily replaced on the Council as a result.
Following her recovery, Billaba took on Caleb Dume as her Padawan, making an important contribution to the future of the galaxy. She gave her life to protect her apprentice during Order 66, ordering him to run while she held back the attacking clones. Caleb would go into hiding, taking the alias Kanan Jarrus and eventually accepted Ezra Bridger as his own student.
Plo Koon
Wise and compassionate, Plo Koon was one of the most effective Jedi masters, genuinely caring about the clones he commanded. He was the Jedi who brought Ahsoka to the Order when she was young, and defended her during her trial for bombing the Jedi Temple.
A skilled pilot, Plo led the 104th "Wolf Pack" Battalion during the war, and proved to be a competent general. In many ways, Master Koon was the perfect mix of what a Jedi should be, wise, compassionate, selfless, and lacking the complacency displayed by many Jedi Masters during the last days of the Republic.
Mace Windu
Prior to the Clone Wars, Windu had served as Master of the Order, and was considered among the most powerful Jedi. Highly skilled in the Force, Master Windu could sometimes appear cold and detached as he kept his emotions in check. He carried a distinctive purple-bladed lightsaber, powered by a rare Kyber crystal.
Despite his high rank, Windu served on the frontline in the war, notably on Ryloth alongside freedom fighter Cham Syndulla. After Anakin revealed Palpatine to be a Sith lord, Windu attempted to arrest the Chancellor. Although his Jedi companions were quickly struck down, Windu managed to disarm Palpatine, and may have killed him if not for Anakin intervening and severing his lightsaber hand.
Obi Wan Kenobi
As Anakin's mentor, Obi Wan's importance began long before his time on the Council. He received his seat at the start of the Clone Wars, following the Battle of Geonosis, and continued to serve throughout the conflict. He was a talented leader, fair-minded and intelligent, and developed friendships with the clones under his command.
After defeating General Grievous on Utapau, Kenobi was caught up in Order 66 and escaped back to Coruscant where Yoda gave him the task of killing Anakin, now Darth Vader. After the fall of the Order, Obi Wan was given the responsibility of protecting Luke Skywalker, something he would give his life to do.
Yoda
A wise and compassionate Jedi, Yoda had learned a lot during his 900 years of life. He often chose not to fight, though he was extremely skilled in all the ways of the Force. The Jedi Grand Master had trained Count Dooku as his Padawan, and also taught all the younglings who came to the Temple, passing his wisdom onto them.
After surviving his defeat at the hands of Darth Sidious, Yoda went into exile on Dagobah, where the planet's strong Force presence could disguise his own. More than two decades later he would train Luke Skywalker in the ways of the Force, even though he had doubts about his headstrong nature and ability to learn.