The JLI Era - A Brief Overview:

The Giffen/DeMatteis Run:

• Begins with Justice League (1987): #1-#6

Renamed to

Justice League International starting with issue #7 up to issue #25 (Note: JLI #13 directly leads into Suicide Squad #13.)

• Following issue #25 the team is split in two - the main book (featuring Martian Manhunter, Blue Beetle, Booster Gold, Fire, Ice, Guy Gardner, and Mister Miracle, plus Max and Oberon) is renamed Justice League America starting with issue #26, while a spin-off book, Justice League Europe (initially consisting of Captain Atom, The Flash, Elongated Man, Power Girl, Animal Man, Metamorpho, and Rocket Red) would launch. The two books would cross over during multiple arcs, including the short Teasdale Imperative arc, and the much more lengthy Breakdowns arc, which serves as the climax for Giffen and DeMatteis's run. Understanding these arcs requires you jump between the two books.

• [Teasdale Imperative reading order: JLA #31, JLE #7, JLA #32, JLE #8]

• [Breakdowns reading order: JLA #53-#60, JLE #29-36 - the reading order is JLA, JLE, JLA, JLE, etc.]

• Another spin-off book, Justice League Quarterly, would launch, which, as the name suggests, was a series of quarterly releases consisting of longer stories. I would highly recommend JLQ for any JLI read-through, as it features some major plot developments (most notably with the Conglomerate storyline in the first issue, which directly follows up on events in JLAmerica #37), and also features some of my favourite JLI-era stories which do a great job at fleshing out the cast.

Below is an exact reading order for the complete Giffen/DeMatteis run (credit to @Atom4087 on twitter):

Post Giffen/DeMatteis:

• Giffen and DeMatteis left Justice League America following issue #60. Following this, Dan Jurgens would take the reins of JLA starting with Justice League Spectacular, a one-shot special which establishes a new status quo for both the JLA and the JLE (most notably featuring the addition of Superman to the team). Jurgens’ run lasts from issue #61 to #77 and notably covers the Death of Superman storyline. Dan Vado would take over starting with issue #78 and his run would feature Judgement Day, another big crossover between the currently running Justice League titles - Justice League America, Justice League Task Force (another spin-off book launched around this time that featured a new 'strike team' with a rotating membership led by J'onn, later refocused into a training ground for younger heroes) and Justice League Europe (which, to add to the confusion, was renamed Justice League International following issue #50 - you'll see this referred to as JLI vol. 2, but note that it's a continuation of JLE, rather than the original JLI run).

• [Judgement Day reading order: JLA #89, JLTF #13, JLI #65, JLA #90, JLTF #14, JLI #66]

• Following Judgement Day, the team would lose their UN backing and another status quo shake-up would lead to the end of the JLE/JLI on-going. It would be replaced by Extreme Justice, which followed the exploits of a splinter team led by Captain Atom who disagreed with the current Justice League team leader, Wonder Woman. Diana's team would continue in the main JLA book, with long-time JLE writer (and convicted pedophile) Gerald Jones taking over starting with issue #93. His run would last until the end of the Justice League America on-going, and the JLI era as a whole, in JLA #113.

Post-script:

• Giffen and DeMatteis would reunite for two comedic miniseries serving as follow-ups to the JLI era: Formerly Known as the Justice League and I Can't Believe It's Not the Justice League, the latter of which was published in the pages of JLA Classified #4-#9, rather than as a stand alone miniseries. This was due to behind the scenes issues regarding how certain JLI characters were going to be used in the Identity Crisis and Infinite Crisis events. Both of these series are included in the Giffen/DeMatteis reading order above.

• A few years later, a 24 issue limited series starring the former JLI members called Justice League: Generation Lost would be released as part of the Brightest Day publishing initiative, written by Judd Winick and Keith Giffen, and serving as a follow-up to events that had occurred in the build-up to and aftermath of Infinite Crisis. A new Justice League International on-going was planned to launch in the aftermath of this series, but unfortunately the New 52 came along and curtailed those plans. A JLI on-going would be published as part of the New 52, but it is very much a reboot rather than a sequel.

Linked below is a Mega folder I put together featuring high quality, (mostly) digital scans of the entire 1987-1996 Justice League era, along with the Superbuddies books, Generation Lost, and miscellaneous related titles and JLI-adjacent issues! You will need an application that can run .cbr and .cbz files to read these - I personally recommend YACReader.

• https://mega.nz/folder/l1hRUBiK#B3BwB9cPpwFXHnaK_9uTFQ

Final note: this is just a very rough overview. I could be far more granular, giving an exact, issue-by-issue reading order of the entire era, including related series like J.M. DeMatteis's Martian Manhunter miniseries and his Mister Miracle run, along with other series and one-off issues featuring the JLI-ers (such as Martian Manhunter 1998 #24, JLA Incarnations #6 and the 1990s Justice League America DC Retroactive oneshot, which reunited Giffen, DeMatties, and Maguire - all three of these are included in the Giffen/DeMatteis reading order above), and I probably will put together something like that someday. But this rough overview should be enough to get you started. Bwah-ha-ha!