Gareth Thomas, the former Wales rugby star who made global headlines in September when he disclosed he has HIV, told Prince Harry—aka the Duke of Sussex—what is was like to receive a positive diagnosis and how it changed his life. Their entire conversation was filmed by the Terrence Higgins Trust, a U.K. HIV charity, and posted online to mark that nation’s National HIV Testing Week, which started on November 16. (You can watch the video above.)

Not that Prince Harry isn’t up to speed about the importance of HIV testing and treatment. His mother, the beloved Princess Diana, who died in 1997, was herself an advocate for people with HIV, and the prince has followed in her footsteps.

“Because I wasn’t educated about HIV, I thought I had been given a death sentence when I was diagnosed,” Gareth, who is gay, told the duke. “I don’t want anyone else to go through that. I want to prove there’s life after a positive diagnosis and show everyone the realities of HIV. I take one pill a day, which keeps me healthy, means I have absolutely no fear of passing on HIV to my husband and means I’m fit enough to do an Ironman!”

He was referring to a triathlon, which involves swimming, running and cycling. Thomas, 45, completed the Tenby Ironman in September, just days after revealing his HIV status to the world.

The Terrence Higgins Trust reported that it saw a major increase in orders for its HIV testing kits after Thomas disclosed his status. A similar surge occurred in 2016 when the Duke of Sussex got tested for HIV live on Facebook.

About 1 in 14 people living with HIV in the United Kingdom don’t know their status, according to data from Public Health England.

In related news, Thomas has been named a commissioner on the United Kingdom’s first-ever HIV Commission. Launched by the Terrence Higgins Trust and the National AIDS Trust, the commission will develop recommendations for ending new HIV cases in England by 2030.

Thomas is also nominated for the 2019 POZ Awards, as Best Celebrity Advocate. To read a list of categories and nominees and to vote for your favorites, click here.

For previous articles in POZ about Thomas, see “Rugby Star Gareth Thomas ‘Forced’ to Disclose He Has HIV [VIDEO],” “Gareth Thomas Coming Out as HIV Positive Offers Hope” and “Watch Rugby Star Gareth Thomas React to News of U=U.”