This Morning remembered agony aunt Denise Robertson in an emotional tribute show following her death from pancreatic cancer at the age of 83.
Presenter Eamonn Holmes broke his sick leave to join his wife, Ruth Langsford, on the sofa to host the ITV programme.
A statement from Robertson's family expressed their grief, but also thanked her fans and the doctors who treated her during her short illness.
"The world has lost an extraordinary woman," they said, "We know that her ITV family, the This Morning viewers and the incalculable numbers of people she has helped and causes she has championed during her 83 years, will be grieving with us at this intensely painful time."
A host of her celebrity friends and ITV colleagues phoned the show to share their memories, including co-presenters Phillip Schofield and Holly Willoughby who called from their holiday destinations.
An emotional Willoughby said: "Whatever she did on screen was just the tip of the iceberg really ... she did so much behind the scenes that nobody saw ... there was nothing she wouldn't do. It's just so sad."
Schofield said that since hearing the news of her illness in February, despite everyone wanting her to return to work, "deep down we knew she was never going to make it back".
Married TV duo Richard Madeley and Judy Finnigan also rang in, with Madeley saying the news "hasn't come as the blind-sided shock that Ronnie Corbett's death was yesterday".
He added: "She did something we all strive to do - she actually made a difference."
Robertson's long-time friend Paul O'Grady described her as "feisty, warm, funny and genuine".
Downton Abbey's Laura Carmichael appeared on the show to talk about her role in the TV drama Marcella, and added her own tribute to Robertson, saying: "She was part of my childhood growing up."
The "matriarch of This Morning" announced six weeks ago that she had been diagnosed with cancer.
Her death was announced on This Morning's official Twitter and Facebook pages.
Robertson, from Sunderland, joined This Morning for its first broadcast in 1988. Her popularity led to her being offered her own TV show in 2000, called Dear Denise.
She made several guest appearances on other TV programmes and was a regular fixture on Channel 5's Big Brother's Bit On The Side.
She was widowed twice - losing first husband Alex to cancer in 1972 and then Jack to a stroke in 1995. She also lost her 44-year-old stepson John to cancer in 2006.
She was awarded an MBE a decade ago and given the freedom of the City of Sunderland.
This Morning's cast and crew ended the two-hour programme with a montage of her TV moments.