The Vulcans are a fan favorite and have been at the core of most Star Trek iterations, ever since the fabled first appearance of Spock, played by the late Leonard Nimoy, in the very first episode of Star Trek: The Original Series (1966–1969). Their species are noted for their ambition to strictly follow logic and reason, attempting to block out as much emotion as possible. Notably, the Vulcan were also the first extraterrestrial species to make contact with humans. Visually they are humanoid in appearance, mainly due to budget restraints. Creator Gene Roddenberry stated that he wanted an alien to be part of the original crew alongside Capt. Kirk (played unforgettably by the by the incomparable William Shatner) to help expand the diversity of the crew past human cultures and races. The budget could not stretch to have an ever-present character in heavy makeup or prosthetics, so the iconic pronounced eyebrows and pointed ears were the best the show could do. Interestingly, this was by Nimoy was chosen, due to his high Slavic cheekbones and “interesting face.”

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The Romulans first appeared in The Original Series as well, and have subsequently appeared in the majority of Star Trek releases since, including season 1 of Picard, mainly as antagonists. They were originally very similar to the Vulcans in appearance, with their pointed ears and glamorous pointed eyebrows, but were given the addition of a v-shaped forehead ridge when they appeared during The Next Generation, reminiscent of the Klingons. In contrast to the Vulcans and their peaceful logic-based culture, the Romulans are shown to be very military-focused, ruling an emotion and war-driven empire.

The relationship and ancestry between the two physically similar, but culturally opposite, species is shrouded in mystery. It’s revealed that the Vulcan and Romulans are descended from the same ancestor species, but sometime before the Vulcans developed their signature devotion of logic, a group of these ancestors split. This was during a time when the Vulcan ancestors were a very different species, emotional and warlike, thriving on colonialism and conquering planets and species across the galaxy. Much like the Roman Empire of human history (consequently a great influence on the design of the Romulans), their empire collapsed under its own weight, and their society descended into chaos.

It’s unknown when exactly the Romulans diverged as their own species, but it is widely considered to be during this time. It’s most likely that they were a group of ancestors that rejected the newfound logic and reason that the Vulcans were trying to pursue, and founded an empire trying to relive their galaxy-domineering ways. Because so much time passed since these events, a lot of the in-universe history has been lost, so it’s unclear what exactly happened. It was also enough time that the Vulcans and Romulans forgot they shared an ancestral history, causing a shock when members of each race met face to face for the first time in centuries, in the Original Series episode “Balance of Terror.”

The relationship between humans and Romulans was expanded upon during this episode, revealing that there was a vicious war between the two in the past. This resulted in a clear divide between Federation space and Romulan space, a neutral zone of agreed peace — as long as nobody crossed into one another’s territory. In the episode, Kirk and his motley crew encounter a Romulan ship destroying Federation outposts in this neutral zone, and hail the crew looking for answers. During the war, nobody had actually seen a Romulan, as the famous view screens had not been implemented yet, so this was the first time anyone on the federation side had seen a Romulan. It was a shock to see how similar they looked to the Vulcans, especially for Spock, who was the first to figure out their shared ancestry.

When looking at the relationship between these two distant cousins, it is easy to compare it to problems faced with problems in today’s society. Yet again, Gene Roddenberry and the creators of Star Trek used science fiction and futurism to provide allegorical stories mirroring topical problems. In the Star Trek universe, the presence of a galaxy full of other species causes the earth to unite under one flag, no longer divided into different races and different ethnicities — everyone is simply human. The same is suggested through the Romulan and Vulcan relationship, a shared ancestry that should unite the warring races, at each other’s throats for being so different, which turn out to be not so different at all.

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