Brenn Tantor was a young man from Garos IV who dreamed of becoming one of the stormtroopers who kept the peace on his world. After his graduation from the Academy of Carida, however, he became much more when he was recruited out of the stormtrooper corps and made an officer in the Imperial Army as part of an elite project. Supervised by Grand General Malcor Brashin, he rose rapidly through the ranks, becoming a prominent general. Tantor reached his height as an Imperial general in 3 ABY when he directed the Battle of Hoth and shortly after that captured Luke Skywalker on Abridon.
When Tantor's brother Dellis, an Imperial Intelligence officer, revealed that the Empire had killed their father, Brenn had a crisis of conscience. After refusing an order to massacre civilians and being told that Dellis had been killed, Tantor finally defected to the Rebel Alliance. After gaining the trust of General Tyr Taskeen, Tantor took a pivotal role in the Rebellion and the New Republic, commanding such engagements as the Battle of Endor and the Liberation of Coruscant. In the latter, Tantor discovered that Dellis had not been killed but was kept in Imperial custody instead—custody from which he was freed, finally reuniting him with his brother.
Tantor's activities after the battle on Coruscant were largely unknown, but the capture of the galactic throne world could only have added to his prestige among the New Galactic Alliance leadership and his tremendous record as an army commander and Supreme Chancellor New Galactic Republic of all people.