If you want to talk about the politics of the Star Trek galaxy, you have to talk about the Romulans. And in order to really understand what's going on in Star Trek: Picard, it's a good time to brush up on your knowledge of the pointy-eared aliens who are not the friendly Vulcans.
Each of the trailers for Star Trek: Picard feature several Romulans, including the sword-wielding Elnor (Evan Evagora), a young member of Picard's new crew, and Narek (Harry Treadway), a bad guy who is clearly up to no good. Additionally, at several points in the trailer, we also see a retro Romulan Bird-of-Prey starship, straight out of the style from the original Star Trek. Notably, Picard also takes place in the aftermath of the future-events of the 2009 Star Trek reboot, in which we learned that the Romulan home planet — Romulus — was destroyed by a giant supernova. So, in theory, the Romulans in the Picard-era will be without a home planet.
Bottom line: The Romulans will be a big deal in the new series. Right now, a three-part IDW comic book series called Picard: Countdown is outlining how Picard tried to help evacuate several Romulan planets while he was still an Admiral in Starfleet. But, the overall history of the Romulans in Star Trek is worth taking a look at.
Here are nine essential Romulan-centric episodes and films to rewatch before Picard debuts.
Note: For episode numbers of individual Star Trek series, I'm using the Netflix order, which, in some cases, will differ from the way the episodes aired. However, this order is easiest if you want to stream these right now.
The Original Series: Season 1, Episode 15, "Balance of Terror"
The very first Romulan episode ever revealed the greatest bombshell ever: They look almost exactly like Vulcans! This revelation seems to shock Mr. Spock, even though, later in Star Trek canon, we learn that the Romulans did split away from the Vulcans in ancient history. Funnily enough, this very first Romulan is played by Mark Lenard, who, in Season 2 of the original Trek would play Sarek, Spock's dad. (Just try not to think about that.)
In any case, "Balance of Terror," is a stand-out episode of the original series, and when Bryan Fuller was in the process of creating Discovery, he listed this as one the most influential episodes ever. Romulan history starts here!
The Original Series: Season 3, Episode 2, "The Enterprise Incident"
Ever wonder why people talk about the "Vulcan death grip"? This episode will answer that question! It's also a great espionage episode for Star Trek, and gives us a deeper look at what Romulans are really like. Plus, you really have to wonder why Spock didn't decide to join the Romulans instead of staying on the Enterprise. They were giving him a pretty good deal, and, after this one, you realize that they're not half bad.
By making the Romulans so similar to the Vulcans, they become a complex enemy for the "good guys." Basically, the Romulans aren't doing anything wrong in this episode, and Kirk and Spock are sort of the aggressors.
The Next Generation: Season 3, Episode 7, "The Enemy"
Although The Next Generation reintroduced the Romulans in the Season 1 finale, "The Neutral Zone," it's not really until Season 3 when TNG starts to really get deep into the political problems between the Federation and the Romulans.
"The Enemy" is a great episode because it really gives you a sense of not only how much Picard distrusts Romulans at this point, but also why Klingons like Worf hate them with a crazy burning passion. Like all good Star Trek, this is an episode about poking at prejudices and talking about the long road to peace.
The Next Generation: Season 3, Episode 10, "The Defector"
This episode rocks. When a Romulan claims he wants to defect to the Federation, Picard can't believe anything the guy is telling him. Following the events of "The Enemy," this episode doubles-down on the mistrust between the Federation and the Romulan Empire, while also giving us new insight into just how deceitful Romulans can be in order to get what they want. Just like with humans, there are good Romulans and bad ones. This fact will surely be a huge part of Picard.
(Also: Both "The Defector" and "The Enemy" feature Trek's most famous — and arguably best — Romulan, Tomalak. This character appeared in four TNG episodes in total and was played by the late, great Andreas Katsulas, equally famous for his long role as G'Kar on Babylon 5.)
The Next Generation: Season 5, Episodes 7 and 8, "Unification Parts 1 and 2"
"Unification Parts 1 and 2" are the moments when Spock (Leonard Nimoy) famously crossed-over to The Next Generation. This was possible not through time travel, but simply because Vulcans live a lot longer than humans. But outside of the novelty and nostalgia of Spock, "Unification" is focused on secret peace-loving Romulans who want to be more like their Vulcan cousins.
Spock is trying to make this happen, but Sela — the half-human/half-Romulan daughter of Tasha Yar — is trying to sabotage them. We won't see Spock in Picard (unless it's a flashback, he went time-traveling before this show starts) but we could perhaps see Sela. And it's reasonable to assume that the pro-unification Romulans still remember that Picard tried to help them.
The Next Generation: Season 6, Episode 20, "The Chase"
Though this episode isn't about the Romulans specifically, it does concern a larger mystery about why all the aliens in Star Trek essentially look humanoid. When the Romulans learn that they might have something in common not just with Vulcans, but with humans, too, there's an important moment where Picard realizes that maybe they won't all be enemies forever.
Deep Space Nine: Season 6, Episode 19, "In the Pale Moonlight"
The Romulans are big players in the galactic politics of Deep Space Nine, and you could go on a huge binge on that series, too. But, the most relevant Romulan episode from that series is one in which Captain Sisko (Avery Brooks) has to try and outright lie to the Romulans in order to get them to do what Starfleet wants. Its a brilliant study in ethics, and is considered one of the finest moments of Deep Space Nine for a reason.
And, like "The Enterprise Incident," this episode is all about the good guys trying to out-fox the Romulans, which is a tricky game to play because the Romulan government is really good at espionage and lying.
Star Trek: Nemesis (2002)
In terms of the regular timeline, the last time we saw the Romulan homeworld, the planet Romulus, Tom Hardy was running the show! This is hard to believe, but in Nemesis, Hardy played Shinzon, a younger clone of Jean-Luc Picard, who was briefly running the Romulan Empire.
Interestingly, Nemesis is also the first time we had any details about the planet Remus, Romulus's sister planet. (Back in the episode "Balance of Terror," Spock mentioned that Remus existed, but we never saw it, or the Remans, until this movie.)
Nemesis is a flawed film and not everyone's cup of Earl Grey Tea. But, in terms of the timeline, this is the last time we saw Picard in action before the events of the new series. And, relevantly, Picard was very hopeful about peace with the Romulans at this point... even though his evil clone was trying to murder him and steal his blood.
Star Trek (2009)
The Romulans in the J.J. Abrams-directed Star Trek reboot may have tried to kill Captain Kirk, Captain Pike, and Spock, but these Romulans are actually from the 24th century, not the 23rd. In fact, chronologically speaking, the backstory of the Star Trek reboot is the closest thing to a direct prequel to Star Trek: Picard. (Other than "Children of Mars," of course.)
When Prime Universe Spock (Leonard Nimoy) mind-melds with Kirk (Chris Pine) in the Kelvin Universe, he reveals that the planet Romulus was destroyed by a supernova, which happened roughly in the year 2387. So, Nero (Eric Bana), the Romulan captain hell-bent on revenge in that movie, is actually from Picard's time, not Kirk's. And Nero's journey back in time will have happened about a decade before the events of Star Trek: Picard.
Now, it's not clear if Picard will reveal why some Romulans started shaving their heads during this time period, but the fact is, the most recent events in Romulan history are depicted in this movie, and because both Spock and Picard tried to help the Romulans at various points in time, you can bet the destruction of Romulus will be mentioned in the new show. A lot.
And, perhaps most relevantly, the co-screenwriter of this film was Alex Kurtzman, who not only is a co-creator of Picard, but also basically the current overseer of the entire Star Trek franchise.