The Retconned Timelines of the Tornado Twins

Getting ready to do an episode covering Impulse #24-25. This one has Bart's mother Meloni coming back in time (for her first appearance) from the 30th century because she wants to take him back home for good. He learns his history and origin but ends up leaving his mom there and going back to the 20th century. This led me down the rabbit hole trying to figure out the history (actually, "histories") of the Tornado Twins, because there appear to be three distinct versions depending on which continuity it is and what's been retconned in or out. I'm pretty sure this is accurate now, but help me out if I missed something important.

Let's explore!

Originally, the Tornado Twins Don & Dawn Allen were introduced as descendants of Barry Allen, aka The Flash from the 20th century. This was later retconned into them being his children, because in the Silver Age when they first appeared, Barry was still alive. Here's the timeline in the original continuity up through Zero Hour (includes the 5YL timeline).

• 2957: Barry Allen arrives in the 30th century of Earth-1 after his trial to try to restart his life with Iris. Tragically, he disappears only a month later, and dies before finding out Iris is pregnant with twins.
• 2958: Don & Dawn born on Earth-1
• 2979: the Legion meets the Tornado Twins. (ADV #373)
• 2981: the twins attend the wedding of Chuck Taine and Luornu Durgo on Mars (LSH v2 #200)
• 2986: the twins are targeted by Professor Ivo in a plot of revenge against descendants of the Justice League (LSH v3 Annual #1)
• 2993: Bart Allen born to Don Allen and Carmen Johnson.
• 2995: Iris Allen wrote a series of articles exposing the Dominators' covert domination of Earth and campaign to wipe out former members of the Legion of Super-Heroes. In revenge, and to prevent others from doing the same, the Dominators fabricated evidence that implicated the twins in the explosion of the Quebec fusion powersphere and had them executed for the crime by the corrupt Earthgov working with the Dominators (LSH v4 #17). Not long after, Iris Allen kidnaps her young grandson Bart, who is rapidly accelerating and aging, and takes him back to the 20th century shortly before Zero Hour in hopes Wally West could help teach and cure him, where Bart becomes Impulse (Flash v2 #91).

Remember, Bart actually first appeared BEFORE Zero Hour.

In the Reboot Legion timeline which came out of Zero Hour, it was revealed that Bart had a cousin Jenni Ognats, who was the daughter of Dawn Allen and Jeven Ognats. Jenni joined the (Reboot) Legion as XS. But she had to be retconned in, so Dawn was now married and had a child. Carmen Johnson was retconned into being Meloni Thawne, a descendant of Eobard Thawne. Further, they wanted to keep the aspect of the Dominators killing the twins, so that got retconned into something different too. With the Silver Age Legion retconned away, these twins never met the Legion, and the Reboot Legion was later revealed (retroactively) to be on Earth-247. In some retellings, Jenni and/or Bart were said to have been aged to teenagers within days, but that doesn't fit the timeline unless she aged naturally (born 2978, joined the Legion in 2994).

• 2957: Barry Allen arrives in the 30th century of Earth-247 after his trial to try to restart his life with Iris. A short time later, he meets his granddaughter Jenni (XS), traveling through time (Legionnaires Annual #3). Tragically, he disappears only a month later, and dies before finding out Iris is pregnant with twins.
• 2958: Don & Dawn born on Earth-247
• 2976 (approx.): Traveling through time, Wally West meets the teenage twins Don and Dawn (Flash v2 #114).
• 2978: Dawn Allen (age 20) marries Jeven Ognats and their daughter Jenni Ognats is born.
• 2980: Don Allen (age 22) marries Meloni Thawne and their son Bart Allen is born. Not long after, Dawn and Don were killed. Meloni was told that they were killed helping overthrow a Dominator invasion and they died nobly in the final battle against the alien forces (Impulse #24), but they were actually killed by Dominator agents with aid from President Thawne and a corrupt Earthgov (LSH v4 Annual #6, Impulse #24), leaving an infant Bart and a two-year-old Jenni. Iris Allen kidnaps her grandson Bart, who is rapidly accelerating and aging, and takes him back to the 20th century in hopes Wally West could help teach and cure him, where Bart becomes Impulse (Flash v2 #91). Bart stays in the 20th century for a couple years (his time) before his mother comes to retrieve him, but he only stays there briefly (Impulse #24-25).
• 2994: Jenni joins the Earth-247 Reboot Legion as XS as a representative from the planet Aarok.

Later, the original Legion was revealed to be still around (in the Lightning Saga storyline). That led to more retconning, with the twins originally being from Earth-Prime and fleeing the Thawnes during the first Legions of 3 Worlds meeting, escaping to Earth-247. That preserved Jenni being able to join the Reboot Legion and the twins being killed by the Dominators; however, I had to move the entire timeline up by 10 years to accommodate Jenni and Bart being aged up by the Dominators and still have Jenni be the correct age when she joined the Legion.

• 2967: Barry Allen arrives in the 30th century of Earth-0 (future home of the Retroboot Legion) after his trial to try to restart his life with Iris. A short time later, he meets his granddaughter Jenni (XS), traveling through time (Legionnaires Annual #3). Tragically, he disappears only a month later, and dies before finding out Iris is pregnant with twins.
• 2968: Don & Dawn born
• 2986 (approx.): Traveling through time, Wally West meets the teenage twins Don and Dawn (Flash v2 #114).
• 2988: Dawn Allen (age 20) marries Jeven Ognats and their daughter Jenni Ognats is born.
• 2990: Don Allen (age 22) marries Meloni Thawne and their son Bart Allen is born. Zoom tries to attack the Twins, but with the help of the first meeting of the Legions of 3 Worlds (L3W #3), the Allen families escape with Iris to find refuge on Earth-247. Shortly after migrating to Earth-247, Dawn and Don Allen were killed by Dominator agents under the guidance of Meloni's father, another sworn enemy of the Allens (Flash Secret Files #1). They left behind an infant Bart and a two-year-old Jenni. (LSHv 4 Annual #6.) The Dominators capture both youngsters, and as a result of experimentation, both are aged to teenagers within days (L3W #3).
• TBD: Jeven Ognats frees Jenni from the Dominators and takes her to his home planet of Aarok. (LSHv 4 Annual #6.)
• 2992: Iris Allen kidnaps her grandson Bart, and takes him back to the 20th century in hopes Wally could help teach and cure him, where he becomes Impulse (Flash v2 #91). Bart stays in the 20th century for a couple years (his time) before his mother comes to retrieve him, but he only stays there briefly (Impulse #24-25).
• 2994: Jenni joins the Earth-247 Reboot Legion as XS as a representative from the planet Aarok.

(Hat tip to Cosmic Teams, Hyperborea (the Flash super-page), the Legion of Super-Bloggers, and the DCU Guide for help with continuity and timelines)