53 years ago - James Gordon is born in Gotham City.
35 years ago - 18-year-old James Gordon attends the Police Academy.
33 years ago - 20-year-old James Gordon becomes a patrolman in Gotham. He meets Sarah Essen
31 years ago - 22-year-old Gordon is the first on the scene of the murder of Thomas & Martha Wayne and gives his coat to young Bruce Wayne, taking care of him.
30 years ago - 23-year-old James Gordon marries Barbara Keen. He moves to Chicago, where he gets his bachelors in criminal justice.
27 years ago - 26-year-old James Gordon adopts his niece Barbara Gordon after her parents die in a car accident.
24 years ago - 29-year-old James Gordon is promoted to Lieutenant.
20 years ago - 33-year-old James Gordon divorces Barbara Keen & returns to Gotham. Barbara Gordon stays with his ex-wife.
15 years ago - 38-year-old Gordon is the only man on the police force Batman trusts when he first surfaces. Gordon mistrusts him at first, but soon they are working together along with Assistant DA Harvey Dent.
14 years ago - 39-year-old Gordon becomes Barbara Gordon's sole caretaker when his ex-wife moves to Europe. He begins seeing Sarah Essen. His work with Batman & Harvey Dent leads to Gotham's DA being brought down on corruption charges.
13 years ago - 40-year-old James Gordon becomes the new Commissioner of the GCPD.
12 years ago - 41-year-old James Gordon marries Sarah Essen.
9 years ago - 44-year-old James Gordon's son James Gordon Jr. is born. Barbara Gordon is shot and paralyzed, and he is tortured by the Joker, but he still refuses to let Batman kill him.
4 years ago - 49-year-old James Gordon is cut out of Batman's mission by Jean-Paul Valley. Gordon is forced treat him as a criminal until Dick Grayson takes over as Batman resolves their relationship.
3 years ago - 50-year-old James Gordon coordinates the GCPD during the No Man's Land earthquake. He receives a "batphone" from Batman. He works alongside Two-Face to secure part of the city. When Two-Face places him on trial for his life he asks for Dent as his defense attorney, notably fracturing his identities.
Commissioner Gordon is the only supporting character in the Batman Universe that has been there from the very first issue. As long as Batman has been a character, Comissioner Gordon has been there.
Almost. the fact is, Gordon is an older character, and in the almost eighty years that the character has existed several writers have flirted with the idea of retiring the Commissioner and replacing him with a new, younger counterpart. There's something to that idea; how long can a man maintain a job like this?
But there's more to Gordon that just a man doing a job. He's Bruce's counterpart. Over the years, he's become more than just the representative of the Gotham Police, he's as bold and vital a hero as Batman himself. Removing Gordon from the story of Batman is removing a key part of who Batman is, which is why every attempt to replace Gordon is ultimately retconned to bring him back.
In our timeline, he's been Commissioner for 13 years. It's certainly been a while, but He's only 50 and has quite a bit more to give before he's ready to think about retiring. That eventual retirement will obviously tie into the end of Bruce's story, delivering on the fatalism that is so clearly a part of who Batman is.
As I write this, Gordon has currently taken over as Batman in the comics, wearing a huge robot suit. Frankly, I appreciate the idea of those comics from a purely experimental, conceptual perspective, but It really doesn't fit in the larger canonical story of Batman. I'll keep my Commissioner with a desk and a revolver, thank you very much.