Star Trekhas only hinted at the events of Admiral James T. Kirk (William Shatner) and the crew of the USS Enterprise’s"lost years". InStar Trek’s timeline, the 5-year mission of Captain Kirk and the Starship Enterprise seen inStar Trek: The Original Seriestook place from 2265-2269.Star Trek: The Motion Picturepicked up in the 2270s, and the rest of theStar Trek: The Original Seriesmoviesfollow a relatively tight chronology from 2285-2293, when Kirk and his Enterprise crew permanently go their separate ways.
Star Trek’s 23rd century is well-documented overall. Although the events of the first four and a half decades of the 23rd century are largely unrecorded, betweenStar Trek: Discoveryseasons 1 and 2,Star Trek: Strange New Worlds, Star Trek: The Original Series, and the first sixStar Trekmovies, there is a clear picture from the mid-2250s to 2293. However, in the years betweenStar Trek: The Motion PictureandStar Trek II: The Wrath of Khan,there are big question marks about what happened to Admiral Kirk and his USS Enterprise crew.

What Star Trek Revealed About Kirk’s Lost Years
Admiral Kirk Retired, Then Returned To Starfleet
Admiral James T. Kirk and the Starship Enterprise share"lost years"that span about a dozen yearsbetweenStar Trek: The Motion Picture, which happened somewhere around 2273, andStar Trek II: The Wrath of Khanin 2285. It’s established canon that after thefive-year mission of Kirk’s EnterpriseinStar Trek: The Original Series, he was promoted to Rear Admiral and made Chief of Starfleet Operations. Kirk returned to Captain the Enterprise inStar Trek: The Motion Picture.
Star Trek: The Motion Picture Ending Explained (In Detail)
Star Trek’s first big-screen adventure ended with a compelling twist regarding the film’s villain and hinted at the many adventures to come.
It’s possible Admiral Kirk commanded the Starship Enterprise on a second five-year mission afterStar Trek: The Motion Picture.Star Trek Generationsestablished that Kirk retired from Starfleet, moved to a mountain home in Idaho, and met a woman named Antonia. Kirk gave a peaceful life of horses and homesteading on Earth the old college try, but the lure of outer space adventures was irresistible. At some point beforeStar Trek II: The Wrath of Khan,Kirk left Antonia and returned to Starfleet.

Where Was Kirk’s Enterprise Crew During Star Trek’s Lost Years?
“If Something’s Important, You Make The Time.”
Star Trekhas only revealed tidbits about how Admiral Kirk’s Starship Enterprise crew spent the lost years from the 2270s to 2285.Spock (Leonard Nimoy) returned to StarfleetafterStar Trek: The Motion Pictureand was promoted toCaptain of the Enterprise. The Vulcan became an instructor at Starfleet Academy, and the USS Enterprise became an Academy training vessel under his command. Enterprise crew members Dr. Leonard McCoy (DeForest Kelley), Hikaru Sulu (George Takei), Scotty (James Doohan), and Lt, Uhura (Nichelle Nichols) remained aboard.
ManyStar Treknovels are set in the"lost years"betweenStar Trek: The Motion PictureandStar Trek II: The Wrath of Khan, but those stories aren’t considered official canon.

Meanwhile, Pavel Chekov was promoted to Commander and became First Officer of the USS Reliant under Captain Clark Terrell (Paul Winfield). At some point,Sulu had a daughter named Demora(Jacqueline Kim), who eventually became helmsman of the USS Enterprise-B. Admiral Kirk last saw Demora 12 years beforeStar Trek Generations' prologue, set in 2293, which would be 2281. It’s unlikelyStar Trekmovies and TV will further explore the events of Kirk and the Enterprise’s"lost years,“but perhaps the fact that the Enterprise and his crew remained in action was what pulled Admiral Kirk back to space.