Relana Isolde Tanoor was the Supreme Chancellor of the Galactic Republic during the early days of the Alsakan Crisis of 13,000 BBY. She was married to Artemis Bac, a Republic solder with whom she had one child, and was the sister of Jedi Master Linora Tristan Tanoor, who later became a leader in the Ospion Guardians. Relana spent most of her life in politics, having been tutored by the Corellian Darik Balc in the traditional subjects of Corellian nobility from an early age. This filled her childhood with a belief in Corellian superiority, although she was later known to have spoken out against prejudice, particularly after her election to the legislative branch of Corellian government in 13,022 BBY.
After working in the Corellian government for four years, Relana was elected as the Senator of Corellia. It was then that she met Artemis Bac, her future husband and the cousin of fellow Alderaan Senator Alcor Bac, for the first time while he was attempting to meet with a Senator that could help him with mining issues on his home planet of Alderaan. She agreed to help him and was able to resolve the issue, after which point she married Artemis and had a son, Adrian Bac, with him. Four years later, in 13,007 BBY, Relana was elected Supreme Chancellor of the Galactic Republic, where she was characterized as having an aggressive stance on exploration and expansion, as well as an open-borders policy.
After the Alsakan Union launched a successful invasion of Coruscant in 13,000 BBY, Relana agreed to a final diplomatic mission of peace in conjunction with the diplomatic efforts of Jedi Grandmaster Banik Kelrada. However, in order to combat the Alsakans in the war, she also created the rank of Supreme Commander and granted it to Army Colonel Arthur Todur. After Relana and Todur began diplomatic efforts with the Opsion Guardians, which was an offshoot of the Jedi Order created after a schism that was the result of the Jedi Conclave on Ossus, Relana was assassinated on Coruscant during her address to the Galactic Senate, which had only just reconvened following a brief recess due to the loss of Coruscant. The assassination created a power vacuum, with Todur positioned to seize control of the Republic in a military coup d'état.