He'd been the only Captain James T. Kirk that Star Trek fans had ever known, having played the role on TV and on the big screen.

And after two decades of leading the crew of the Starship Enterprise, a question was posed to William Shatner about his ability to carry on playing the beloved character indefinitely.

Star Trek's Leonard Nimoy and William Shatner are seen in a 1978 file photo. They and the other cast members reprised their roles together in a half-dozen big-screen movies. (AP/JLR)

"Are they going to have to replace you? Could they do that?" Midday host Valerie Pringle asked Shatner, during an interview in the late summer of 1987.

Shatner met the question head on, just like viewers would expect the captain of the Enterprise to do.

"I'm sure they can," said Shatner before adding, "I'll fight them tooth and nail."

'Never could have imagined it'

William Shatner discusses his longlasting role as Captain James T. Kirk. 1:19

The actor admitted he did not foresee the role of Captain Kirk being such a long-lasting gig — more than two decades and counting at that point. (And it had lasted much longer than the original series, which only was on air for three seasons.)

"Never could have imagined it in a million years," said Shatner.

The Montreal-born actor said it was hard to say exactly what had made Star Trek such an enduring franchise. He told Midday that a long career in showbiz — with work on stage, including at the Stratford Festival, as well as on television and film — had shown him things didn't always turn out the way you thought they would.

William Shatner is seen playing Marc Antony in a production of Julius Caesar, which aired on CBC in 1960. (Dale Barnes/CBC Still Photo Collection)

"I've been in shows going into Broadway that long before it got to town, there was a box office line," said Shatner. "And I've equally done the opposite, that it's been publicized and everyone's read about it and nothing happened."

Shatner, of course, would continue to play the Kirk character on the big screen through several further Star Trek sequels.

In recent years, however, a rebooted Star Trek movie franchise has seen actor Chris Pine play the Enterprise captain at a younger age.