Many have battled to become the king of late night television, but there was never any question about who was the mother of late night TV: Dave's mom.

Dorothy Mengering was the mother of late night host David Letterman and became a famous comedian in her own right. The pie-baking Hoosier was a frequent guest and roving correspondent for her son during his 33-year comedic reign on network television.

Ms. Mengering died on Tuesday. She was 95.

She leaves behind three children, five grandchildren and a TV legacy unlike any other.

Her daughter Gretchen Letterman, who spent 31 years as a journalist at the Tampa Bay Times, said the family enjoyed watching their mother blossom on TV and more than hold her own with one of the greatest wits of all time.

"We just all loved the fact that she shined in her unexpected second career as a television star," said Gretchen Letterman, 61, the youngest of Ms. Mengering's three children. "I was just so very proud of her in that role.

"She wouldn't take any stuff from him, which was what was so funny. Even though she let him fill her fridge with Colt 45 malt liquor and bags of White Castle, when he would say something really ridiculous, she would say: 'Oh David, that's not true.'

"She was the perfect foil for him."

Rolling Stone ranked (and likely underrated) Ms. Mengering as David Letterman's fourth best "second banana" on late night TV, behind Larry "Bud" Melman, Chris Elliott and band leader Paul Shaffer.

"She clearly loves her son while politely tolerating his foolishness with the sort of doting affection only a parent understands," the magazine said, praising her Midwestern charm and noting that while celebrities and even presidents always called her son "Dave," she was the only one who called him "David."

Ms. Mengering was born in Linton, Ind. She was an avid reader as a child, her favorites the tales of adventure, hardship and nature by Indiana author Gene Stratton Porter, which she continued to read over and over again late in life.

She was studying at Indiana University and visiting home on weekends when she met her first husband, H. Joe Letterman, who played the organ at church. They married in 1942 and headed to Indianapolis, where Joe Letterman opened a florist shop and they kept their own backyard garden long before it became chic.

They had three kids, Gretchen, David and eldest sister Janice Millholland, who would give Ms. Mengering her first two grandkids starting in 1967.

Joe Letterman died at the age of 57 in 1973. Ms. Mengering spent the next decade doting on her two grandchildren. Meanwhile her son went from Indiana TV weatherman to Los Angeles stand-up comic to one of the most prestigious jobs on television: fill-in host for Johnny Carson on The Tonight Show Starring Johnny Carson.

Then she met her second husband, Hans P. Mengering. They married in 1983, a year after Late Night with David Letterman debuted at the 12:30 a.m. time slot on NBC. Foreshadowing the mother's television career, the Mengerings traveled to Europe and across the U.S., where they often visited a new generation of grandchildren in Florida. That's where daughter Gretchen Letterman worked as features editor for the then-St. Petersburg Times.

Ms. Mengering's path to stardom as "Dave's mom" started in 1994 after her son's infamous exit from NBC and move to CBS to host the Late Show with David Letterman. He sent her to the Winter Olympics in Lillehammer, Norway, with a camera crew.

It was there that she asked then-first lady Hillary Clinton if the president could do something about the speed limit in Connecticut, which her son struggled to obey. Clinton invited Ms. Mengering to the White House but left it up to her whether she wanted to bring along her son.

Ms. Mengering became a favorite on the show, reading off Top 10 lists that poked fun at her son and visiting the studio for her birthdays and Mothers Days.

In 1996, Ms. Mengering published a cookbook "Home Cookin' with Dave's Mom," which included his favorites such as his annual birthday treats, "Hot Baloney Sandwich" and "Sour Cherry Pie." She made David Letterman his favorite fried baloney sandwich on the show, during which he accused his mother of stealing recipes from Dairy Queen. Her cookbook raised money for Kiwanis International to help children overseas.

Meanwhile CBS sent her to the 1998 Winter Olympics in Nagano, Japan, the 2002 winter games in Salt Lake City, Utah, and the city of London.

Ms. Mengering also loved to bake, and her son planted a camera in her kitchen in Carmel, Ind., so everyone could watch. Once she even baked pies with fellow Hoosier and rock star John Mellencamp at home. Every Thanksgiving, she challenged her son to guess what homemade pies were cooling on the counter. It was not his strong suit.

"After dinner what are you going to be doing there in Indiana?" her son asked during one of many guest appearances from her kitchen.

"Two words, David: Old Milwaukee," Dave's mom said.

Spending time with family was her "idea of a good time," according to her obituary, and she enjoyed the five decades she spent with her grandchildren.

Her second husband, Hans Mengering, died in 2013. David Letterman retired in 2015. That year, he told Indianapolis Monthly that his mother was recovering from a stroke.

"She had a stroke a couple of weeks ago, but she's fine. She's 94, for heaven's sake. If I had a stroke, I'd be hospitalized for the rest of my life. My mom has one, and she's fine."

Dave's mom died a day before her son's 70th birthday.

Gretchen Letterman posted this message to Facebook after her mom's passing:

" 'Old age is not for sissies,' " Dorothy said often, with certain pride that she knew darn well she was not one. Peace to my dear, dear mother, who this afternoon decided it was finally time to say goodbye."