Before cinematic universes took over the box office, one network quietly built its own multiverse — not with superheroes, but with military heroes, courtroom drama, and elite investigators. And it all started with JAG.
Created by television mastermind Donald P. Bellisario — the man behind Magnum, P.I., Airwolf, and Quantum Leap — JAG may not have set out to launch a sprawling television ecosystem, but 30 years later, its DNA runs through some of the biggest CBS hits of the last two decades, including NCIS, Magnum P.I., Hawaii Five-0, and MacGyver.
Move over, Marvel — this is TV’s original multiverse.
From ‘JAG’ to Juggernaut
JAG (short for Judge Advocate General) debuted on NBC in 1995, with David James Elliott starring as Commander Harmon “Harm” Rabb and Tracey Needham as Lt. Meg Austin. The show followed Navy lawyers who investigated military crimes, inspired in part by the 1991 Tailhook scandal. While the Navy initially distanced itself from the show, fearing it was anti-military, their stance changed once they realized JAG portrayed its legal officers as heroes.
Despite Bellisario’s reputation, JAG struggled in the ratings on NBC. After one season, CBS took a gamble and retooled the series, transforming it into a more grounded courtroom drama. Tracey Needham was replaced with Catherine Bell, who joined as Marine attorney Sarah “Mac” MacKenzie. That pivot paid off: JAG ran for another nine years on CBS, officially wrapping in 2005 — but unofficially, the world of JAG was just getting started.
The Rise of NCIS
Enter NCIS, the procedural powerhouse that premiered in 2003 as a backdoor pilot within JAG. In the two-part arc “Ice Queen” and “Meltdown,” audiences met Special Agent Leroy Jethro Gibbs (Mark Harmon) and the original NCIS crew, as they investigated the murder of Lt. Loren Singer — a plot that even saw Harm arrested.
From that dramatic introduction, NCIS was born — and the rest is history. Created by Bellisario once again, the spin-off quickly became CBS’s crown jewel. Now entering its 23rd season, NCIS has become one of the longest-running scripted dramas on television and has spawned multiple spin-offs of its own, including NCIS: Los Angeles, NCIS: New Orleans, NCIS: Hawai’i, and NCIS: Origins.
NCIS: Los Angeles, in particular, brought the JAG connection full circle when both Elliott and Bell reprised their roles as Harm and Mac in 2019. In a multi-episode arc, Harm is now a Navy captain commanding the USS Intrepid, while Mac is pulled in to assist the LA team with diplomatic clearance. For longtime fans, it was a nostalgic and satisfying reunion.
Crossovers in Paradise: Hawaii Five-0, Magnum, P.I., and MacGyver
The JAG–NCIS universe expanded even further in 2010 with CBS’s reboot of Hawaii Five-0, led by Alex O’Loughlin as Steve McGarrett, a Navy Reserve Lieutenant Commander. While Five-0 carved its own niche as a high-octane island procedural, it also embraced crossover potential — most notably in a 2012 two-night event with NCIS: Los Angeles. The storyline saw agents from LA and Hawaii teaming up to track down a suspect, and later, prevent a bioterrorism threat involving smallpox.
That crossover magic didn’t stop there. Executive producer Peter M. Lenkov, riding high on Five-0’s success, developed reboots of MacGyver and Magnum, P.I. for CBS. These shows didn’t just exist in the same network — they existed in the same world.
In Season 1 of MacGyver, the Phoenix Foundation team travels to Hawaii to assist in earthquake relief — cue a crossover with Five-0. In 2020, Magnum, P.I. returned the favor with a two-part event involving stolen CIA intel and a rescue mission, pairing McGarrett with the new Thomas Magnum (played by Jay Hernandez).
While none of these shows directly referenced JAG, their link to NCIS: Los Angeles — and thus to Harm and Mac — creates a web of connections that all trace back to Bellisario’s original military legal drama.
A Legacy Built on Order and Action
It’s easy to forget now, but JAG began as a struggling mid-’90s series on NBC. Now, it’s essentially the keystone in one of television’s most expansive and interconnected franchises. Without it, we wouldn’t have NCIS — and without NCIS, the modern CBS procedural universe likely wouldn’t exist as we know it.
As network television continues to shift in the age of streaming, JAG‘s legacy remains surprisingly modern. Its influence has quietly shaped CBS’s programming philosophy: compelling characters, serialized storytelling with procedural roots, and the occasional crossover event to keep fans guessing.
In a media landscape obsessed with shared universes, maybe it’s time we gave credit where it’s due. Before the MCU, before the Arrowverse — there was JAG.
