Crown Princess Mette-Marit of Norway, center, with French Minister of Health Marisol Touraine and UNAIDS executive director Michel Sidibe at the Red Ribbon Award at the 2012 International AIDS Conference. (Brendan Smialowski/AFP/Getty Images)

But they’re probably all outranked by Elton John as the celebvocate of longest tenure devoted to the issue. The singer gave an emotional keynote calling AIDS an epidemic “fueled by stigma,” and said it’s only dumb luck that he didn’t contract the illness during his reckless, self-loathing youth. “We have to replace the shame with love.”

Yet remember, he’s only Sir Elton — and this conference also had a princess.

She is Crown Princess Mette-Marit of Norway. We caught up with her Wednesday night after she co-hosted with Messing at Population Services International’s Impact Awards reception at the Corcoran — one of those very Washington affairs where do-gooers strain to deliver their messages about circumcision rates in Africa and CD4 analyzers over the din of cocktail chatter.

Like Kate Middleton, Mette-Marit, 38, is one of those commoners who seems born to have become a queen: A towering blonde radiant in a coral lace dress and minimal makeup.

AIDS has not always been her issue, she told us. Before she met Prince Haakon, the single mother (yes, a mild scandal at the time) was active in social justice causes. But becoming a princess gave her a platform. The young royals started a health foundation to mark their 2001 wedding, and its mission slowly evolved when the country’s development minister asked her to represent Norway through the UN’s AIDS program.

A “life-changing trip to Malawi” packed more of an emotional punch than she thinks her escorts intended, she said:

“I had a 1-year-old baby” — the youngest of her three, Prince Sverre Magnus — “and I met all these women who had newborns, sitting there with babies literally dying in their arms.”

What does a princess do at an AIDS conference? Panel discussions, community center visits and a lot of networking — her specific task, she said, is to link Norwegian youth activists with policy makers. But she only had two days before flying out again, to the Olympics.

Busy schedule, huh? “I’m on a break from my holiday,” she said with a smile.

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