[2] As first conceived by writers, Bart was born in the 30th century to Meloni Thawne and Don Allen, and is part of a complex family tree of superheroes and supervillains.

On his mother's side, he is a descendant of supervillains Professor Zoom and Cobalt Blue as well as the half-brother of Owen Mercer, the second Captain Boomerang.

Allen was subsequently absent for nearly two years after his apparent death, but resurfaced—young again—as Kid Flash, in 2009's Final Crisis: Legion of 3 Worlds.

The original Bart Allen was brought back as part of DC Rebirth's Wonder Comics Young Justice series.

As depicted in a Legion of Super-Heroes story, Barry Allen's children—the Tornado Twins—were arrested in A.D. 2995 by the government of Earth, which had fallen under the covert control of the Dominators.

[8] Bart joins the Titans early in his career before becoming a founding member of Young Justice alongside Robin and Superboy.

[5][20][21] In The Flash: Rebirth, Bart discovers that Barry Allen was resurrected during his time in the Speed Force, having been killed years prior during Crisis on Infinite Earths.

[29][30][31] Sometime after Blackest Night, Cyborg recruits Bart and Superboy to rescue Static, who has been kidnapped while visiting his hometown of Dakota.

[32][33] At the behest of Tim Drake, Bart travels to Gotham City and saves Catwoman from members of the League of Assassins while she is sleeping in her apartment.

[34] Shortly after settling back in Titans Tower, Bart reveals to Conner that during his brief stay in the future, he went through records concerning technology from the era.

He also tells Conner that he is losing his memories of this future information due to the time stream being corrected, and that he is writing down everything he can remember.

[37] The Earth is a changed alternate timeline, where Bart Allen wakes up in the 31st century in Brainiac's stasis pod chamber and has lost his super-speed.

[39] However, Bart's body was transforming into Black Flash that had been controlled by the Speed Force, taking him to reduce the speedsters Max Mercury, Jay Garrick, and Wally West.

[42] Shortly afterward, he reunites with his former Young Justice and Teen Titans teammates Robin (Tim Drake) and Wonder Girl (Cassandra Sandsmark).

[46] Bart's primary power is speed, along with abilities that are common to comics speedsters, such as creating whirlwinds, running on water, and vibrating through matter.

The latter ability results in "molecular taffy" if Bart does not concentrate; he also possesses an aura, that prevents air friction while running.

Bart has the ability to recall everything he has ever read, heard or watched (which includes speed-reading every book in the San Francisco Public Library), allowing him to spout encyclopedic information concerning the situation at hand as well as quotations from Mark Twain, of whose work he is fond.

[48] After remembering his experiences on an alternate Earth during a fight with Griffin, he began to gain a measure of control over the Speed Force before it was released from his body just prior to his death.

Since his first appearance in The Flash #91, Bart had been trained by several speed-endowed heroes such as Jay Garrick, Johnny Quick, and Max Mercury.

Prior to his reluctance to don the red and yellow, Bart showed a lot of enthusiasm toward his role as the future Flash.

He is a reactionary from a dystopian planet Altros Prime in the far future who was sent to the 21st century as part of a witness protection program and sustained amnesia.

[50] Following the death of Max Mercury and Helen Claiborne, Bart returns to the future to be with his mother, while his girlfriend Carol Bucklen came along.

The corrupt President Thawne, Bart's grandfather, takes their research and forms the Hyperguard, a group of soldiers with superhuman speed.