Talia Adira al Ghul was born to the wife of Ra's al Ghul in a hellish prison known as The Pit. She grew up in the prison, protected by a fellow prisoner called Bane, who loved her. As a child, she managed to climb out of the pit and escape. She then moved to Gotham City and became a businesswoman ostensibly interested in clean energy, but secretly loyal to the League of Shadows' plan to destroy the city.
When attending a memorial for Harvey Dent at Wayne Manor, Tate attempted to meet with Wayne but was placated by Alfred Pennyworth. She continued attempting to see Wayne in order to discuss his fusion project, but didn't until a party she threw was attended by Wayne. She spoke to him, and he agreed to show her the fusion reactor. Later she spent the night with Wayne and talked to him of her childhood.
Later Bane took the executive boardroom hostage and took Tate with Lucius Fox and Douglas Fredericks down to the reactor. He threatened Fredericks' life if Fox didn't unlock the reactor, and Tate persuaded Fox to do it. Bane then had his scientist Leonid Pavel turn the reactor into a bomb, and hold the city hostage.
Tate then volunteered with James Gordon and John Blake to help take down Bane. When they were tracking the bomb-laden trucks, they were all captured. They were sentenced to exile over the ice, but Bane held Tate back, posing as a hostage. When Batman returned to Gotham to save Tate, and overpowered Bane, Tate stabbed him in the back and revealed herself as Talia al Ghul. She then told Bane to keep Bruce alive until the bomb went off, and got into the bomb truck to keep it from being disabled. Batman chased her in The Bat, and the truck crashed in a tunnel. However, Tate then flooded the reactor chamber so the bomb could not be disabled. Batman flew the bomb away from Gotham and the city was saved.