After cameoing in Batman v Superman: Dawn of Justice, Aquaman made his full DC Extended Universe debut a year and a half later in Justice League. At the end of that movie, Jason Momoa's Arthur Curry was seen swimming in the ocean, setting the stage of his soon-to-be-arriving solo movie. However, it turns out there was more to Aquaman's Justice League wrap-up intended to be shown involving supporting characters Mera and Vulko. In Momoa's words:
In Zack's cut, we had it where I was with Vulko and Mera, and I say that I have to go home. And they say there's this force coming that I need to help. I'm like, 'I'm going home to see my dad.' I get into the back of a pickup truck and pound a bottle of something and off he goes, the wanderer. So that was kind of the end of Justice League - where I was going. Cut to me coming home and run into a submarine.
Jason Momoa provided this information after being asked by WSVN-TV's Chris Van Vliet when exactly Aquaman takes place after Justice League, noting that in his mind, the former happens right after the latter. Momoa also mentioned that in Aquaman, Arthur Curry has been gone for so long that he wants to come back to his roots, hence why he goes to visit his dad, Thomas Curry, played by Temuera Morrison. However, the theatrical cut of Justice League ultimately tossed out this look into his personal life and instead just showed him embracing his Atlantean half more than before.
Given that Justice League was an ensemble piece, it was to be expected that the move could only spend so much time delving into Aquaman's mythology. After all, the filmmakers also had to ensure Batman, Wonder Woman, Flash, Cyborg and (later on) Superman got enough screen time. Still, as most of you reading already know, the Justice League that director Zack Snyder originally envisioned and shot during principal photography differed quite a bit from the one that Joss Whedon oversaw the creation of following Snyder's departure. Cutting out this scene with Arthur Curry, Mera and Vulko was just one of the casualties.
Fortunately for Amber Heard's Mera, she still got a little screen time in Justice League, as she did her best to protect Atlantis' Mother Box from Steppenwolf. Unfortunately for Willem Dafoe's Vulko, he was removed from the movie completely, leaving it up to Aquaman to introduced him. Both he and Mera will be integral allies to Arthur Curry as he finds himself taking the Atlantean throne and trying to prevent a war between the surface world and the Atlanteans who are sick of humanity polluting the oceans.
Aquaman dives into theaters on December 21. In the meantime, look through our DC movies guide to learn what else the DCEU has coming down the pipeline.