Three different characters related to Captain James T. Kirk have held the name Samuel Kirk in various iterations of the Star Trek franchise.

Throughout the Star Trek franchise, there have been three different George Samuel Kirks, the name held by both the father and brother of Captain James T. Kirk (William Shatner/Chris Pine/Paul Wesley). Since his introduction in Star Trek: The Original Series, Captain Kirk has become one of the most iconic characters in all of science fiction. Due to the nature of television in the 1960s, most episodes of TOS told standalone stories. Because of this, not much information was shared about Kirk’s past or his family unless it directly related to the story of the week.

The first George Samuel Kirk was the father of James T. Kirk and Samuel Kirk, and was not officially introduced until J.J. Abrams’ Star Trek (2009), as portrayed by Chris Hemsworth. Named after his father, Samuel Kirk (Dan Jeannotte) did not become a fully realized character until Star Trek: Strange New Worlds, where he serves on the USS Enterprise commanded by Captain Christopher Pike (Anson Mount). The current television tradition of more serialized storytelling and more focus on franchise canon has allowed modern Star Trek films and television shows to dive deeper into the backstories and family histories of the characters.

Lt. Commander George Samuel Kirk In Star Trek’s Prime Timeline Explained

Kirk’s father was a high standard to live up to.

In Star Trek’s Prime Timeline, not much has been revealed about James and Samuel Kirk’s father, George Samuel Kirk. George joined Starfleet because he truly believed in its mission, and he spent much of his time traveling around the galaxy away from his family. When James T. Kirk (Paul Wesley) was born, George and his wife, Winona, were living in Riverside, Iowa, but the family would often travel as George moved from posting to posting. George was incredibly dedicated to his Starfleet career, and he became the youngest Starfleet officer to achieve the rank of First Officer – a record that would later be broken by his son, James Kirk.

As a child, James wondered why his father would choose to help strangers rather than spend time with his family, but James later came to see the importance of his father’s career. James Kirk joined Starfleet because of his father, and followed in his footsteps, quickly climbing through the ranks. Sam, on the other hand, had different views about what made a successful career, and he preferred spending time in a science lab. Very little was learned about George or Winona Kirk over the course of TOS, and they did not get more fleshed out until J.J. Abrams’ Star Trek in 2009.

Lt. Commander George Samuel Kirk In J.J. Abrams’ Star Trek Explained

The Kelvin Timeline’s George Kirk commanded a starship for 12 minutes.

In Star Trek (2009), Lieutenant George Kirk was serving as the First Officer of the USS Kelvin under the command of Captain Richard Robau (Faran Tahir). When the Kelvin was called to investigate a singularity, they encountered the Romulan ship Narada commanded by Captain Nero (Eric Bana), which had traveled back in time from 2387. Despite Captain Robau’s attempt to negotiate a ceasefire, the Narada continued to fire, eventually crippling the Kelvin. Left in command of the ship, George Kirk ensured everyone was evacuated, including his pregnant wife, Winona (Jennifer Morrison).

After the Kelvin’s autopilot failed, George had to remain on board to prevent the Narada from firing on the escaping shuttles. George protected the shuttles and set the Kelvin on a collision course with the Narada. Although George was killed in the crash, he saved the lives of 800 people and disabled Nero’s ship. Just before the two ships crashed, George spoke with his wife as she gave birth to their son, James. Because of Nero’s disruption to the Prime Timeline, the James Kirk (Chris Pine) of the Kelvin timeline grew up without a father, never feeling the same pull to join Starfleet. In this timeline, it was Captain Christopher Pike (Bruce Greenwood) who encouraged James to enlist in Starfleet.

Lieutenant George Samuel Kirk In Star Trek: Strange New Worlds Explained

Everyone calls him Sam.

Although the character of James’ brother, George Samuel Kirk, was technically introduced in Star Trek: The Original Series, Lt. Sam Kirk did not appear alive on screen until Strange New Worlds. Played by Dan Jeannotte, Jim Kirk’s older brother Sam served on the Enterprise of Captain Pike as a xenoanthropologist. Sam sometimes felt that he couldn’t live up to the achievements of his younger brother, especially in the eyes of their father. Sam had an understandable fear of the Gorn but still volunteered to help rescue the survivors of a Gorn attack on Parnassus Beta in the Strange New Worlds season 2 finale.

At some point relating to James T. Kirk becoming Captain of the Enterprise, Sam leaves Starfleet and accepts a civilian posting on a research station. By this point in his life, Sam was married to his wife Aurelan (Joan Swift), and had three sons, including one named Peter (Craig Hundley) who survived the parasite attack that killed his parents. In 2266, a visiting ship brought dangerous parasites to the station where Sam and his family lived. The parasites began attacking the colonists indiscriminately, killing Sam and mortally wounding Aurelan before she could get a distress signal out to the Enterprise. By the time Captain Kirk and the Enterprise arrived, Sam had already died, bringing a tragic end to his Star Trek story.