Prince Harry was at the Attitude Awards Thursday night, accepting an award on behalf of his mother, Princess Diana, for her pioneering AIDS activism.

Two decades after Diana's untimely death, Attitude magazine gave her its Legacy Award, honoring her work helping to remove the stigma associated with HIV/AIDS during the height of the crisis.

"In April 1987, my mother was only 25 years old,” Harry said in his acceptance speech. "She was still finding her way in public life, but already she felt a responsibility to shine her spotlight on the people and issues that were often ignored. She knew that AIDS was one of the things that many wanted to ignore and seemed like a hopeless challenge. She knew that the misunderstanding of this relatively new disease was creating a dangerous situation when mixed with homophobia."

Referencing her famous handshake with a hospice patient, Harry said, "She was using her position as Princess of Wales—the most famous woman in the world—to challenge everyone to educate themselves; to find their compassion; and to reach out to those who need help instead of pushing them away."

The prince has been following in his mother's footsteps—visiting HIV clinics, attending the International AIDS Conference in South Africa, and taking an HIV test on Facebook Live to encourage testing.

Although he's sure his mother would be proud of his work, Harry told the audience he has taken up the cause because, as a straight man, he can help fight the stereotype that HIV is a "gay disease."

"The issue itself needs a straight guy, mid-30s, to come in and try and normalize it," he remarked in the BBC documentary The Truth About HIV. "Once again, I’m fortunate enough to be in this position in order to make a difference."