John Proudstar was born on an Apache Reservation and served in the Army. After leaving the military he was approached by Professor Charles Xavier and offered a chance to join the X-Men. He accepted on the condition his brother James could join as well. Xavier agreed.

In the months that followed, John and James proved their worth. Tragically, James was killed while fighting Count Nefaria. John, feeling responsible, left the X-Men for some time. He returned months later at the same moment as Apocalypse attacked the X-Men. Unleashing his anger on Apocalypse, Thunderbird was able to save the X-Men, but was captured during Apocalypse's retreat.

Apocalypse experimented on Thunderbird, transforming him into the Horseman of War. John eventually broke free of Apocalypse's mind control and defeated his master. He then returned to the X-Men and attempted to pick up the pieces of his life.

The Timebroker summoned T-Bird, as he was calling himself now (because he felt more like a car than a bird), and met his fellow Exiles in a barren desert. The Timebroker told him that if he did not help the Exiles complete their missions he would remain Apocalypse's servant.

During a mission in which the Exiles had to save Alpha Flight from an insane Hulk, T-Bird met an alternate version of himself who had become Shaman. The two bonded and T-Bird was reminded of who he was before Apocalypse took him.

T-Bird would also defeat the Hulk by unleashing the full fury of his Apocalypse-created battle mode. Following the battle, John and Nocturne began a relationship that would blossom into love. T-Bird would try to end the relationship, feeling he was not worthy of Nocturne, but she would stick by him. On an Earth ruled by the Skrulls the team was captured. While in captivity, Nocturne told T-Bird she was pregnant. The Exiles eventually escaped but only because the Skrulls evacuated the planet due to the arrival of Galactus.

During battle with Galactus, T-Bird sacrificed his own life to save the world. John planted a bomb on Galactus' armor but was caught in the blast and critically injured. Nocturne, believing John would recover, assumed the Exiles would wait for him to get well. That was not the case. Team then teleported away and left James behind.

He was later revealed to be transferred to Stasis Gallery in Crystal Palace by the Timebreakers, but was still in a comatose state. Recently, T-Bird woke up from his coma and rejoin the Exiles.