Trebek, who has hosted Jeopardy! for 30 years, in 2005.
Art Fleming hosted the original daytime game show, which debuted in 1964.
Fleming hosted alongside announcer DonPardo. The original daytime version of Jeopardy! made its debut on NBC March 30, 1964, and was an immediate ratings hit.
The daytime version of the show ran for 2,753 episodes.
Trebek as host of the quiz show in 1984.
In 1984, Sony TV launched the daily syndicated Jepoardy! -- the show still on the air today -- with Alex Trebek as host and Johnny Gilbert as announcer. It went on to win 30 Daytime Emmys and a Peabody in 2012.
Merv Griffin (right) in 1974. He created Jeopardy!, Wheel of Fortune and many other game shows.
Merv Griffin and Donald Trump
Donald Trump presents Merv Griffin with the 1990 Scopus Award from the American Friends of Hebrew University on Jan. 15, 1990.
"Jeopardy! is reality TV in a broader sense as well: It encompasses all of reality, the entire known universe," Ken Jennings, who holds the win streak record with 74 straight victories, writes for THR in a tribute to the show.
Griffin, who retired from The Merv Griffin Show in 1986, is shown here during his final episode.
A True Star
The longtime host got his Walk of Fame star in 2006.
Trebek on Contestants
"I'm just enjoying what I'm doing. I'm happy to have a job. I like the show, I like the contestants and it pays well," says Trebek.
Jennings on Jeopardy! in 2004 during his epic winning streak.
Does the longtime host worry about retirement? "I don't worry about it at all," he says. "When it happens it will probably happen the same way it happened when I shaved my mustache in 2001: It will happen on a whim. I will decide at that moment, 'This is it. Leave me an extra 30 seconds at the end of the program so I can say goodbye.' "
Trebek holds the Guinness record as the person who has hosted the most TV game shows, topping Bob Barker.