We've just made it through a bunch of time travel in The Flash, and we're about to embark on some more time travel, so I thought I'd do a quick post explaining all the different timelines we've seen. Analyzing the time travel in the comics can be confusing, because the point of reference is always the ambiguous "now." So I've assigned some arbitrary years to these events, keeping in mind that time moves much slower in comic books than real life. Events such as Gorilla Warfare and Forever Evil took about half a year to come out, but the actual story only lasted a couple of days.
In 2011, Barry Allen learned that Eobard Thawne had traveled back in time and killed his mother. So Barry went back to prevent that horrific event, but accidentally created the bleak world of Flashpoint. He eventually was able to travel back in time again and stop himself from saving his mom, but (with some manipulation by Pandora) Barry didn't return everything completely back to normal, and actually created a new timeline, which coincided with DC's launch of The New 52. We'll call this ...
In Timeline A, Barry Allen became the Flash approximately in the year 2006. He joined the Justice League soon after and helped them repel Darkseid's invasion. In 2011, Flash battled Mob Rule and the newly super-powered Rogues. In 2012, Flash fought off Gorilla Grodd from invading Central City, took on the Reverse-Flash, and was involved in the Trinity War and Forever Evil events.
Using 2012 as our "now," we can say that Wally West was killed in 2017 — an event which slowly began Barry's descent into madness. In 2019, the Trickster accidentally killed a young family and committed suicide. In 2024, Captain Cold died of cancer, and in 2028, Mirror Master accidentally killed 11 people. In 2032, Flash killed Gorilla Grodd and began his trek backward through time. Because he wore a blue suit, I call him Blue to distinguish him from the past, sane versions of the Flash.
Blue's first stop was in 2028, where he prevented Mirror Master from killing 11 people. By doing this, and allowing Sam Scudder to die, Blue created a new timeline. But since we don't see anything result from this new timeline, we'll just call it Timeline A' and move on.
Blue then visited Leonard Snart on his deathbed in 2024, but he didn't change anything, so no new timeline was created. But he did create Timeline A'' when he prevented Trickster from killing a family and convinced Axel Walker to not commit suicide.
Once again, this new timeline is virtually meaningless for our narrative, as we don't see anything post-2019 with a good Trickster. The same applies for the quick series of changes Blue makes after that — stopping the Top from also committing suicide, and rescuing a couple of groups of people.
All in all, Blue created at least five new timelines that we really don't care about. But he did create a new, significant timeline in 2017, when he saved Wally West's life and killed the Reverse-Flash. We'll call this ...
After killing Daniel West, Blue battled the current version of the Flash. The two Barrys created a massive Speed Force-induced explosion, which sent Blue further back in time, killed the current Flash, and gave Wally super speed. Wally spent several years training and studying his powers before mastering time travel and finding the insane Blue in the year 2012, which by this point was now ...
Wally sacrificed himself to save the current Barry's life. But after Wally died, Barry was sucked into the Speed Force, and Blue assumed his identity for a few days. Eventually, Barry escaped the Speed Force, and teamed up with Blue to defeat Selkirk. Blue died in the battle, leaving only the current Flash behind, and bringing everything (more or less) back to normal. It is possible to use one of these time-travel jumps to explain the slight differences between The Flash #0 and Secret Origins #7 ... if you obsess over continuity as much as I do.
So hopefully this didn't make things more confusing. Next time, we'll begin DC's weekly series called Futures End. As the title suggests, it takes place in the future, but (surprise, surprise) it doesn't match up very well with what we saw in The Flash. In Futures End #0, we'll start 35 years from now (2047) in what I believe could be considered a continuation of this new Timeline C. I'll explain more when I review that issue.