By John Dodge

CHICAGO (CBS) — CBS announced on Thursday that Stephen Colbert will succeed David Letterman on “The Late Show.”

Colbert, 49, is a graduate of Northwestern University, where he was a theatre major. Colbert returned to NU in 2011 to give the commencement address.

In a radio interview with CBS News, CBS President and CEO Leslie Moonves said Colbert will not portray his Comedy Central character when he hosts “The Late Show.”

Colbert's Career Launched In Chicago

Letterman in a statement said: “Stephen has always been a real friend to me. I’m very excited for him, and I’m flattered that CBS chose him. I also happen to know they wanted another guy with glasses.”

While attending college, he studied and performed improv comedy at Annoyance Theatre and ImprovOlympic (now the iO Theater) in Chicago.

After graduating from Northwestern in 1986, and traveling in Europe, Colbert began working at The Second City answering phones. When he found out employees could take classes for free, he signed up, and ended up joining the famous comedy troupe in the same class as Chris Farley, Amy Sedaris and Paul Dinello.

He also performed alongside future The Daily Show teammate Steve Carrell. The two were in the very first show Kelly Leonard produced. Now executive vice president at The Second City, Leonard said Colbert had a rare combination of intellect and playfulness.

“You usually don’t get both of those. You get a writer type who’s kind of reserved, or you get the playful jump all around kind of guy, and Stephen was both,” he said.