On Friday night, however, she stepped with her husband Prince Albert to honour one of Monaco's highly anticipated annual celebrations.
The 32-year-old princess, who is believed to be around five months pregnant, wore a floor-length navy blue gown, dazzling diamond earrings and a jewelled head band for the 66th Monaco Red Cross Ball.
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Representing the Monegasque royal family, Albert and Charlene dined with guests including Shirley Bassey, French actor Francois Cluzet, Princess Camilla, Duchess of Castro and jazz musician Marcus Miller, before enjoying a spectacular firework display.
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Gareth Wittstock, Charlene's younger brother, also attended the glittering gala, which was held in the lavish Salle des Etoiles of Monte-Carlo's stunning Sporting Club.
The room was a sea of scarlet decorations and the tables were decked with bouquets of pink and green flowers.
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Built by Albert's father Prince Rainier III, the Sporting Club has hosted the ball ever since its foundation in 1948 which was presided over for many years by his consort, Princess Grace.
Following Princess Grace's death, Albert's sisters Princess Caroline and Princess Stephanie took up the mantle.
Albert and Charlene take to the dancefloor at the Red Cross Ball
In 2013 royal watchers were excited to see Princess Caroline at the ball, having recently become a grandmother to Andrea Casiraghi and Tatiana Santo Domingo's son Sacha. This year, however, all eyes were on Charlene as she prepares to welcome her first child.