Prince William was the closest to Princess Diana's heart, but he did not use the relationship to mollycoddle her for something "off" that she did.

Two years after Prince Harry was born, Prince Charles reportedly restarted his romantic entanglement with Camilla. Apparently, Princess Diana knew what was going on during that time.

According to Andrew Morton's book entitled "Diana: Her True Story," the Prince and Princess of Wales reached the rock bottom of their relationship since there were "three people" involved in the marriage. Princess Diana personally confirmed to a Panorama interview that she was aware that her husband was having an affair with Camilla, one year before the royal couple got divorced in 1996.

On the same year, the then 15-year-old Prince William and 12-year-old Prince Harry often spoke about their mother and continuously grieved for her.

In the ITV documentary "Prince William at 30," it was revealed that Prince William thought that her mother has "gone too far" when she brought humiliation onto the Royal Family in her Panorama interview.

Katie Nicholl, a royal commentator, also said that the Duke of Cambridge snubbed Princess Diana for days, and the mother felt the worst considering how close they were.

"He was desperately upset, could not believe that she would lay her soul so bare," BBC's ex-royal correspondent Jennie Bond said.

Prince William's Advice Before Divorce

The Prince and Princess of Wales officially ended everything between them in 1992 and formally divorced in 1996. But the 14-year-old Prince William, despite his young age, left words of love for her mother and helped her survive the tormenting event.

The narrator of "Prince William: Royalty in My Family" claimed that the duke wanted to end Princess Diana's suffering as soon as possible. However, a speedy divorce meant Princess Diana would need to give up her royal title.

"You'll still be mummy," Prince William said, trying to comfort his mother.

The Duke of Cambridge protected the royal princess until she tragically passed away when she got into a car accident in Paris a year after her divorce with Prince Charles. Princess Diana was together with her then-partner Dodi Fayed and driver, Henri Paul.

Prince William Loves Mom!

In the same documentary, It was revealed that even when Prince William was just nine years old, he took Princess Diana to her favorite restaurant to cheer her up.

It has been 22 years since the Princess of Wales passed away, but the duke still showed support for her late mother and reminisced her good deeds.

Prince William continues to support Centrepoint, Princess Diana's patronage -- which is a charity located in the basement of St. Anne's Church in London. Prince William recently attended its 50th Anniversary Celebration.

Currently, the charity undertakes its "most ambitious project" ever as it aims to expand across London and Manchester in two years. Centrepoint also plans to offer employment opportunities for the less-fortunate youth.

With its current plans to expand the charity, Princess Diana is sure smiling from above and feeling proud of what Prince William has become.

READ MORE: Prince William Wants Princess Diana's Charity Shut Down -- Here's Why