Andrea Casiraghi and Tatiana Santodomingo, then his girlfriend, arrive at the Place du Palais to attend the religious wedding ceremony for Monaco's Prince Albert II and Princess Charlene at the Palace in Monaco July 2, 2011. Casiraghi and Tatiana will tie the knot on 31 August, 2013. (REUTERS/Jean-Paul Pelissier)
Andrea Casiraghi and Tatiana Santodomingo, then his girlfriend, arrive at the Place du Palais to attend the religious wedding ceremony for Monaco's Prince Albert II and Princess Charlene at the Palace in Monaco July 2, 2011. Casiraghi and Tatiana will tie the knot on 31 August, 2013. (REUTERS/Jean-Paul Pelissier)

Prince William and Kate Middleton, both 31, may be the ultimate royal heartthrobs but they are not the only glamorous young royals around - a few new faces are in the making.

First there was Princess Madeleine of Sweden (the daughter of King Carl XVI Gustaf and Queen Silvia), who married American-British banker Christopher O'Neill. The two wed at the royal castle in Stockholm on 8 June.

And now the Monaco royal family is next in line, with Andrea Casiraghi set to enter holy matrimony.

The eldest son of the principality's hereditary princess, Caroline, the Princess of Hanover, will tie the knot with Colombian socialite fiancée, Tatiana Santo Domingo, on 31 August, the Associated Press confirmed.

Casiraghi, 29, is also the eldest grandchild of former Hollywood actress Grace Kelly, who completed her own fairytale story by marrying Prince Rainier III of Monaco in 1956. He was officially engaged to Tatiana, six months elder, in July 2012, after dating her for seven years.

The soon-to-be royal couple welcomed their first child, a baby boy named Sacha, in March. And once legitimised by the wedding of his parents, Sacha will be third in line to Monaco's throne; after his grandmother, Princess Caroline, and father.

Casiraghi's unmarried younger sister, Charlotte Casiraghi, is expecting her first child with her fiancé, French actor and comedian Gad Elmaleh, by the end of this year.

Meanwhile, as we await wedding photos of Andrea Casiraghi and Tatiana, here are a few archival photos of the couple...

Andrea Casiraghi and Tatiana Santodomingo pictured (Left) on the wedding day of Monaco's Prince Albert II and Princess Charlene in 2011; they arrive (Right) for Valentino's party at the Temple of Venus in Rome July 6, 2007. After being together for more than seven years, the two will wed on 31 August. (REUTERS)
Andrea Casiraghi and Tatiana Santodomingo pictured (Left) on the wedding day of Monaco's Prince Albert II and Princess Charlene in 2011; they arrive (Right) for Valentino's party at the Temple of Venus in Rome July 6, 2007. After being together for more than seven years, the two will wed on 31 August. (REUTERS)
Andrea Casiraghi and Tatiana arrive for a screening of U.S. director Sofia Coppola's in-competition film 'Marie Antoinette' at the 59th Cannes Film Festival May 24, 2006.( REUTERS/Eric Gaillard)
Andrea Casiraghi and Tatiana arrive for a screening of U.S. director Sofia Coppola's in-competition film 'Marie Antoinette' at the 59th Cannes Film Festival May 24, 2006.( REUTERS/Eric Gaillard)
Andrea Casiraghi and Tatiana welcomed their first child in March 2013. (REUTERS/Eric Gaillard)
Andrea Casiraghi and Tatiana welcomed their first child in March 2013. (REUTERS/Eric Gaillard)
Andrea Casiraghi is second in line of succession to Monaco's throne after his mother Caroline, Princess of Hanover and Heriditary Princess of Monaco.  (REUTERS)
Andrea Casiraghi is second in line of succession to Monaco's throne after his mother Caroline, Princess of Hanover and Heriditary Princess of Monaco. (REUTERS)
Andrea Casiraghi is the eldest grandchild of Princess Grace and nephew of Monaco's ruling sovereign prince Albert II. (REUTERS)
Andrea Casiraghi is the eldest grandchild of Princess Grace and nephew of Monaco's ruling sovereign prince Albert II. (REUTERS)