It’s almost impossible for NCIS fans to imagine Mark Harmon as anyone other than Leroy Jethro Gibbs. But when Harmon first received the script, he wasn’t even sure he wanted the job.

At the time, Harmon had a young family and was hoping to spend more time at home. Then one small detail caught his attention: the name Leroy Jethro Gibbs. Harmon later admitted that the unusual name was one of the things that made him stop and take notice of the character.

Then something surprising happened. Creator Donald P. Bellisario briefly changed Gibbs’ name to something Harmon remembered as “Bob Johnson or something like that.” Harmon pushed back, insisting that the character needed to remain Leroy Jethro Gibbs. The original name was restored.

There was another twist: Bellisario initially wasn’t convinced Harmon was right for Gibbs, reportedly thinking of him as too much of a “pretty boy.” Seeing Harmon’s dramatic work on The West Wing changed his mind.

The rest became television history. Harmon went on to make Gibbs one of the most recognizable characters on American television — and it’s strange to think how differently NCIS might have turned out if those early decisions had gone another way.