Star Trek made history in the late 1960s when the first season of The Original Series aired, setting a precedent for many, if not all, space faring science fiction media that followed. Over the years it created a plethora of iconic moments, character, and technology, some of which acted as genuine inspiration for modern day technology. Of these characters there are the classics, the ones people who haven’t even seen the shows or movies will recognize, such as Captain Kirk, the much-memed Spock, and Picard, but there is one who has become an internet sensation: Chief Miles O’Brien.
O’Brien, born Miles Edward O’Brien, is one of those characters that was carried through more than one Star Trek show, appearing frequently in The Next Generation, as well as being one of the major characters aboard the Deep Space 9 station in DS9. The well-loved character was played by Colm Meaney, and first appeared as an unnamed Starfleet officer donned in red during the very first episode of The Next Generation, “Encounter at Farpoint.” He next appeared, still during Season 1, in the episode “Lonely Among Us” as another unnamed officer, this time a security guard. It was only during Season 2 that he gets a name and a position, sticking with the gold uniform but this time as the transporter chief fans didn’t realize they needed.
He gets a bit more characterization at this time too, joining the senior staff in a game of data run poker, as well as being invited to Worf’s party. He continues to mill around in the background, marrying Keiko and doing a very memorable musical number with his one time captain Benjamin Maxwell during the episode “The Wounded.” For a lot of fans, this was the point where they fell in love with the sometimes grumpy Irish transporter chief. His song was both beautifully sung and heartbreakingly sad, as it’s the moment he persuades his former captain and friend to surrender to the Federation for his renegade actions against the Cardassians. This, mixed with his down-to-earth personality, made him a likable and pragmatic everyman that audiences could empathize with. O’Brien strongly believed himself equal to his fellow crew, even those below his rank.
The producers must have realized that they had struck gold with O’Brien. When DS9 began, they promoted him in 2369, making him Chief of Operations for both the space station and their ship, the US Defiant. During the series, he quickly became a pivotal part of the crew, and played important roles in many of the show's storylines. He fought in the catastrophic Dominion War alongside Captain Sisko. It was during these hard times that he finally came clean in the last episode of DS9, “What You Leave Behind,” to his dear friend and station medical officer Dr. Julian Bashir. He admitted that he had been offered a teaching position at Starfleet Academy, and after the war was over he planned to take it.
The position was to be a Professor of Optronic Systems Engineering, and it is assumed that he takes it. His main reason to teach and return to the safety of Starfleet was primarily to spend time with his family, but he also joked that it was important as someone needed ‘to teach [officers] the difference between a warp matrix flux capacitor and a self-sealing stembolt.’
This is where things ebb in and out of cannon, as there are various non-canon novels that explore what O'Brien does after this point. He and Keiko are sent to Cardassia during the two novels Cardassia: The Lotus Flower and The Never-Ending Sacrifice to help the plant as part of various Federation led relief projects, Keiko being in charge of renewing the planet's flora after its destruction during the Dominion War.
After this, life was fairly quiet until 2383, when during the novel Raise The Dawn the Deep Space 9 space station was destroyed by the ‘Typhon Pact,’ a group of disgruntled interstellar states formed after the Borg Invasion in 2381. It was following this destruction that O’Brien returned and became the chief engineer for both the station that was being built, and the facility on Bajor that oversaw its construction. Later, in the year 2387 at the age of 55, he was promoted yet again to Command Master Chief Petty Officer and served beside Captain Ro as his right-hand man, in the novel The Ashes of Tomorrow. If the trill symbiont Jadzia Dax is to be believed, he lived a long life and died from old age surrounded by his family.
This is where things return somewhat to canon, depending on what is to be believed about the legitimacy of the animated show Lower Decks. In the episode “Temporal Edict,” the show flashes forward to the far future and see a Starfleet classroom who are learning about all the noteworthy historical figures in the Federation. Among these is Chief O’Brien himself, whom they have erected a gold statue of, and is referred to as the most important person in Starfleet history.
While this may seem like a throwaway joke or reference for the episode, it perfectly summarized both what fans think of the wonderful Irish engine wizard, but also symbolized all the amazing things he did in his life. He was not just another captain soaked in glory, but a working class officer who rose through the ranks strongly upheld everything the Federation stood for.