In the history of the show, and through many regenerations, The Doctor has come up against many enemies, one of which is the Sontaran race. The warrior race is both a formidable foe and strong ally, known across the universe as elite soldiers only driven by honor in battle and militaristic success. Here’s a deep dive into these super soldier aliens and their impact on the classic show.

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The first appearance of the Sontarans came in the 1973 serial “The Time Warrior,” in which the Third Doctor (Jon Pertwee) and the iconic companion Sarah Jane Smith (Elisabeth Sladen) meet Linx the Sontaran in medieval England. Sontarans are a humanoid race, squat and stocky with more than a slight resemblance to a potato. Linx has crashed his ship when bandit Irongron and his group of merry men come across the invader. Linx promptly lays claim to Earth, and offers Irongron and his men highly advanced weapons in exchange for shelter while he fixes his ship.

The Doctor and Sarah Jane Smith become involved when scientists from the 20th century start disappearing. It becomes apparent that Linx is traveling to the future, kidnapping scientists, and hypnotizing them to help finish fixing his ship. The Doctor steps in to stop Linx, save the scientists, and prevent Irongron from taking over the area with the futuristic weapons. By the end of the serial, Linx is dead and the early seeds of Sontaran history have been sown. Linx is killed when he is struck in the back of the neck, where his ‘probic vent’ is. The Sontarans use this vent to refuel, and it is also the species’ main weakness.

As the Sontarans made further appearances in the show, more of their history was established. In the expanded media of the universe, it was revealed that the Sontarans are from the planet Sontar, but weren’t the original inhabitants. The race was created by the Kaveetch. As they were genetically engineered and unable to propagate naturally, the Sontarans continue their species through cloning. Engineered for war, the Sontarans are engaged in an endless war with the Rutans, something that they have no desire to change and actively enjoy.

In the modern series episode “The Sontaran Strategem,” The Doctor praised them as “the finest soldiers in the galaxy.” Sontarans are also not allowed, nor do they seem to desire, to take part in recreational activities, although they do seem to consider hunting a sport. When the Sontarans prepare for battle, they can be heard yelling their battle cry “Son-tar-ha!” Many Sontaran names are characterized by the beginning sound of “St.” General Styre, Stor, Staal, and fan favorite Strax are just some examples. There are others with names that subvert this like Linx, Varl, and Kaagh, but they seem to be outliers.

The Sontarans were fan-favorite villains, appearing several times in the original series until 1977. Once the series was revived in 2005, Russell T. Davies decided to bring the galactic warriors back with a slight redesign, and played up their comedic elements a bit more. The personality of the Sontarans is very deadpan and matter-of-fact, not dissimilar to David Bautista’s portrayal of Drax in Guardians of the Galaxy, adding a distinct brand of humor to any episode in which they appear — yet, their deadliness is not to be underestimated.

Once the Sontarans began appearing in the new series, there was a subtle shift in the attitudes towards them. Although they were always smug and superior, they did become funnier. Still villains and definitely up to no good, the Sontarans became more likable. Despite trying to terraform Earth during the Tenth Doctor’s stint and joining up with other enemies of The Doctor in “The Pandorica Opens” and “A Good Man Goes To War” in the Eleventh Doctor’s story, the Sontarans are one of the least scary Doctor Who villains.

This image perception was in part also due to the introduction of Strax the Sontaran, who became a beloved recurring character in the revival series. Strax was first seen in the episode “A Good Man Goes To War,” along with the Silurian Madame Vastra and her human wife Jenny. The three are enlisted by the Eleventh Doctor as part of the rescue effort of Amy Pond. Strax is initially introduced as a nurse, tending to the battle wounded. This is a great position of shame for a Sontaran, and is used as a form of punishment. Strax dies in the battle to save Amy, but in a webisode titled “The Battle of Demons Run: Two Days Later,” he is woken up by Madame Vastra and Jenny, leading to him joining them in the 19th Century as their butler. From there the three became known as the Paternoster Gang, and would pop up from time to time to aid The Doctor in sticky situations.

Since the Paternoster Gang, there have only been two Sontaran appearances, one in 2015 which is extremely brief where a Sontaran appears as a refugee. The next main appearance was in the Thirteenth Doctor’s Flux saga, in which Sontarans appeared in the hope of exploiting the Flux crisis to take over the Earth at different points in history. Their efforts were ultimately scuppered by The Doctor, marking the most recent Sontaran appearance in the series.

Where can the Sontaran story go from here? Re-establishing them as a threat in the recent episodes increases the chances of the warriors appearing again. Their advanced technology and propensity for using hypnosis to make people do their bidding allow for a lot of future threats. Although the return of the Sontaran threat would be a welcome move for fans, what many are hoping for is a return of Strax and the Paternoster Gang, who haven’t appeared in a mainstream episode of the series since 2014.

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