Flash's History
Bart Allen is a teenage speedster and a member of the Flash Family who has gone by several codenames. He was born in the 30th Century, the grandson of time-traveling speedster the Flash, although he returned to the past to continue his family's legacy. Because of his strange origins, he ages at an inconsistent rate. Originally, he took the name Impulse to reflect his impulsive nature, but later changed his alias to Kid Flash when he grew older. There was a brief period when he became The Flash after Infinite Crisis, but he was killed by the Rogues during Full Throttle. Later on, he was resurrected during Final Crisis through his connection to the Speed Force and has returned to his role as Kid Flash since then. Bart Allen has been a member of the New Titans, Young Justice, the Teen Titans, and the Legion of Super-Heroes.
Early Life
Bart Allen was the product of the union between two families who had been bitter rivals for centuries. His father, Don Allen, was the son of Barry Allen, the second Flash, and his mother was Meloni Thawne, daughter of the Earthgov president and descendant of Flash villains Cobalt Blue and Professor Zoom.
Shortly after Bart's birth, his family was attacked by Zoom, wishing to end the union of the rival families. They, along with the family of Don's sister Dawn, attempted to flee to a parallel Earth using the Cosmic Treadmill. However, Zoom sabotaged the device, causing an explosion which created a rift in the multiverse. Zoom was ultimately defeated by an army of three different Legions of Super-Heroes, but Bart and his family were subsequently stranded on Earth-247.
Bart was born with his grandfather's speed. He had an incredibly high metabolism and also aged at hyperspeed. When he was chronologically two years old, physically, he appeared twelve years old. President Thawne had the Dominators killed Don and his twin sister, Dawn Allen. The Dominators then abducted Bart, who was later captured by Earthgov for observation. The scientists of Earthgov raised him in a virtual reality environment so that he aged as swiftly mentally as he did physically. Bart was going to die of old age very quickly, with Earthgov not doing anything to fix his problem. His grandmother Iris West took him away and brought him back to the twentieth century, so that her nephew, Wally West, the third Flash, could show him how to control his speed.
He later adopted the superheroic identity of Impulse.
Impulse
After Wally helped him solve his problem and Bart helped him to defeat Kobra, Bart moved to Manchester, Alabama with Max Mercury. Wally had used his connections to supply Bart with a birth certificate, etc. Bart began the ninth grade at Manchester Junior High. He managed to make quite a few friends, chief among them Carol Bucklen. Max continued to train him in the art of superspeed, having him run obstacle courses while dodging axes and knives, solve jigsaw puzzles in mid-air, etc. During this time, he became one of the founding members of Young Justice.
Following Max's disappearance, he was taken in by Jay Garrick, the first Flash, and his wife Joan Garrick.
Kid Flash
Following the breakup of Young Justice, Bart joined the new Teen Titans. He soon had his kneecap blown out by Deathstroke (who was at the time possessed by Jericho) and replaced with an artificial one. While recovering, Bart read every single book in the San Francisco Public Library and reinvented himself as the new Kid Flash. Even with the artificial kneecap, he could still run close to light speed. After Superboy-Prime attacked Superboy (Conner Kent) in Smallville injuring and killing many Titans, Bart joined with Wally West and Jay Garrick to stop the rampage of Superboy-Prime by running him at top speed into the Speed Force. Jay reached his limit before entering the Speed Force and Wally turned into energy and vanished, leaving Bart alone with Superboy-Prime. Barry Allen, Johnny Quick and Max Mercury, all of whom had previously been absorbed into the Speed Force, appeared and aided Bart. After taking Superboy-Prime into the Speed Force, Barry told Bart that "Wally is waiting for you". After they disappeared, Jay claimed that the Speed Force was gone.
A speedster wearing Barry's costume returned in Tokyo shortly thereafter to warn of the return of Superboy-Prime. This same Flash, still wearing Barry Allen's costume, would appear in the middle of the Battle of Metropolis against the army of escaped super villains. Superboy-Prime reveals that the person in the Flash costume is Bart Allen, aged 4 years older. Bart explains to the nearby Wonder Girl (who was surprised by her fellow Titan's transformation) that his grandfather's uniform was the only thing that could survive the trip back from where he had been, and that he was the only one there "who could still run". Bart then unleashed his anger against Superboy-Prime for killing Conner Kent, pummeling him at superspeed and forcing Superboy-Prime to retreat from the battle. When the crisis was over, Bart explained to Jay that he spent years in an unknown dimension where time passed quicker, causing him to grow older. Bart confirmed that the Speed Force was destroyed and he used up the residual speed locked in his body fighting in Metropolis. He gave Barry's costume to Jay and says Jay was now the fastest man alive once again.
Flash: The Fastest Man Alive
Bart shunned his superheroic past for the next year. He received a job working at Keystone Motors and began sharing an apartment with another young man named Griffin Grey. However, he was still connected to the Speed Force, but the connection threatened to kill him. S.T.A.R. Labs modified one of his grandfather's old costumes to help him control his connection. While at first he refused to don the costume, he finally gave in and became the fourth Flash.
He also began a relationship with S.T.A.R. Labs employee Valerie Perez.
Bart decided to get a fresh start and moved to Los Angeles, applying for a job in forensics with their police department.
Inertia hired the Rogues to help him build a device in Los Angeles with the purpose of transferring the Speed Force from Bart to himself. Despite warnings from his grandmother, Bart confronted them. The machine was successful in removing his powers, but in doing so, it threatened to detonate with the energy of several atomic bombs. Bart sacrificed himself heroically, distracting the Rogues while Val deactivated the machine.
A funeral was held for Bart in a stadium in Keystone City. It was attended by a large number of costumed heroes, including his former Teen Titans teammates Robin, Wonder Girl, Raven and Beast Boy, and televised around the world. Eulogies were given by Jay Garrick, who revealed Bart's secret identity to the world. The funeral ended with the presentation of a video he had recorded shortly after becoming Kid Flash, to be shown in the event of his death.
Recently during Final Crisis: Legion of 3 Worlds, XS charged a lightning rod with the assistance of different versions of Garth and Ayla Ranzz in order to restore Bart to life. Bart returned as a teenager again and he received his Kid Flash costume ring from Brainiac 5.
The Flash: Rebirth
Rebirth is the recent comic The Flash: Rebirth, which features the return of Barry Allen, the Silver Age Scarlet Speedster and Bart's grandfather. At Titans Tower West, a newly returned Bart Allen views his grandfather's return with skepticism, admitting a desire for things to "go back to the way it used to be" with Wally as the primary Flash and himself as Kid Flash, as well as feeling angry that Barry is the only one to escape the Speed Force and not Max Mercury. Bart, along with Superboy, is resurrected, but Death hunts them down to reclaim their lives.
Blackest Night
With Bart and Conner Kent's return, both of their statues were removed from the Titans Tower "Hall of Fallen Titans" memorial. However, Nekron, the personification of Death, sought reclaim their lives during the Blackest Night crossover. Bart, along with Wally, raced across the globe to warn every hero of the Black Lantern Corps' invasion. Bart later arrived at Coast City with Wally and scattered members of the Justice League and Teen Titans to take a stand against Nekron, who was responsible for the Black Lanterns. Despite being resurrected, Bart's previous status as a deceased still allowed one of the undead lord's black rings to transform him into a Black Lantern.
After his grandfather is chosen as a Blue Lantern by Ganthet of the Guardians of the Universe and leader of the Blue Lantern Corps, Bart immediately engages battle with him. Barry's blue power ring detects that Bart is still alive but he would eventually die if not freed from the black ring soon. Barry nearly releases Bart from the black ring using blue energy constructs crafted in the images of Bart as Impulse and Kid Flash, before being interfered by Black Lantern versions of Professor Zoom and Solovar. Wally and Blue Lantern Bro'Dee Walker join Barry against them. Bart attempts to use his speed powers to kill Wally, only to be temporarily returned to normal. Realizing that their mutual connection to the Speed Force can save Bart, Barry uses his powers to break the ring's connection, freeing him.
Return to the Teen Titans
Sometime after Blackest Night, Bart and Conner were recruited by Cyborg to help rescue a current Titan by the name of Static, who had been kidnapped while visiting his hometown of Dakota. The three heroes arrive at the scene of a battle between the Teen Titans and a superhuman gangster named Holocaust, and intervene just as he is about to finish off the their comrades. Bart and Conner then comment that it's time for them to come out of "retirement" and rejoin the Teen Titans. Holocaust simply laughs and tells them to bring it, and Bart responds by saying "We were hoping you'd say that". After a lengthy battle, Bart deals the finishing blow to the villain by running around him fast enough to open a vacuum which sucks him into the Earth's inner core.
At the behest of Tim Drake, Bart travels to Gotham City and saves Selina Kyle from members of the League of Assassins while she is sleeping in her apartment. After knocking out the would-be killers, Bart remarks to Tim over the radio that Selina is "super-fine", and that this may be the best day of his life.
