Pierre Rainier Stefano Casiraghi (born 5 September 1987, Centre Hospitalier Princesse Grace in Monte Carlo, Monaco) is the younger son of Caroline, Princess of Hanover, and her second husband, Stefano Casiraghi.

He is named after his maternal great-grandfather, Prince Pierre of Monaco, his maternal grandfather, Prince Rainier III of Monaco, and his father. His godparents are his uncle Prince Albert and his aunt by marriage Laura Casiraghi (the wife of Daniele Casiraghi).

Pierre was just over three years old at the time of his father's death in a boating accident.

He has two older siblings: Andrea Albert Pierre Casiraghi and Charlotte Marie Pomeline Casiraghi, and one younger half-sister, HRH Princess Alexandra of Hanover.

He can speak fluent French, Italian, English and some German. He also plays the saxophone.

He is currently living and studying in Milan, Italy. He is enrolled in an economics course at the Bocconi University.

The Italian and British celebrity magazines, such as Diva e Donna, Chi or Hello have been printing occasional updates on his social life in Milan or Paris, showing pictures of him with the likes of socialite Olympia Scarry, British beauty Alice Dellal, Monegasque heiress Emma-Sóphie Bergdorf Grimaldi, French ballerina Emilie Fouilloux and more recently Italian aristocrat Beatrice Borromeo as well as models Caroline Winberg, Fernanda Lessa.[citation needed] The Spy column in the Daily Telegraph has said that he leads a very opulent lifestyle with a GBP 2,000-per-month apartment in Milan's trendy Brera district. It is believed that he will use his economics degree towards learning the business of his father's companies that are, in the meantime and since his father's death,being managed by Pierre's uncle Marco Casiraghi.

Source: Wikipedia