The royal brought her husband to tears in an emotional speech celebrating his 10-year anniversary on the throne

By Peter Mikelbank
Updated July 12, 2015 12:20 PM
Credit: Pascal Le Segretain/Getty

Princess Charlene brought her husband to tears on Saturday.

Monaco’s stylish royal, 37, joined her husband, Prince Albert, in the Palace Square to celebrate his 10th anniversary on the throne.

Speaking in French for for the first time in public, she surprised both her husband and the crowd with an unexpected personal note.

Referring to his forebears, she said, “[Prince] Albert I was the Explorer, Rainier III was the Prince-Builder, and you are the Prince of Hearts, of my heart.”

A visibly moved Prince Albert, 57, wiped back tears and kissed his wife. Charlene touched her heart and pointed at her husband.

Moving to the microphone, Albert seemed at a loss for words: “They told me you had a surprise for me today. But that …”

In an exclusive interview with PEOPLE last week, Albert praised his South African-raised wife of four years, saying, “She’s coming into her own now. I think she’s found a good space. I think I underestimated her.”

Speaking to a reporter in the crowd, Prince Albert’s sister Princess Stephanie said, “It was very moving. For me, for everyone … It was a beautiful moment. Very beautiful. A surprise for everyone.”

Charlene’s brother, Gareth Wittstock, seconded the emotion. “I think it was very spectacular. What she did, speaking in French. It’s a very difficult language but she did a great job at it. Fantastic. I think Monaco’s also very proud of her.”

Related Video: Princess Charlotte’s Christening to Be Photographed by Famed Fashion Photographer Mario Testino

The couple’s 7-month-old twins, Gabriella and Jacques, also attended the grand anniversary festivities. Dressed in white and pink and by held by nannies on the palace balcony, they were presented with baptism gifts from the citizens as part of the afternoon ceremonies.

Among the presents: a 1925 Cartier belt buckle brooch (for Gabriella) and a Cartier tank watch gifted by the mayor of Monaco, Georges Marsan.