The family made their fortune through brewing, but went on to own an airline, newspapers and a television channel.Forbes magazine listed her grandfather, also named Julio Mario, as the 108th wealthiest man in the world and the second wealthiest in Colombia, with a net worth of .5 billion (£5.5bn).Her husband, second in line to the throne after his mother, has lead an equally gilded existence in the company of his siblings.His brother Pierre, 25, a model alongside Jeremy Irons for Italian cobbler Berluti, studied in Milan and now runs his late father's construction companies.Hers was the definition of a privileged upbringing; living in Geneva until she was 15, with summers spent in Bali, she studied first in Paris and then London, before completing her education with a masters in visual communications at the New School in New York.She currently works as a stylist, running an online boutique named Muzungu Sisters – the word "muzungu" means traveller in Swahili – and is a regular on the front row at international fashion exhibitions.His girlfriend Beatrice Borromeo, 28, is a member of an Italian dynasty that can trace its roots back to the 12th century, and she has modelled for Chanel and Cavalli, while her uncle Count Matteo Marzotto was the chairman of the fashion designer, Valentino.The wedding was a suitably glamourous gathering for the couple, who met in 2002, when Miss Santo Domingo was studying alongside Mr Casiraghi's sister Charlotte at a private Catholic school, the Lycee Jeanne-D'Arc-Saint-Aspais in Fontainebleau, near Paris.
There was not a crown to be seen, and no massed ranks of European royals.
But the marriage of Andrea Casiraghi, second in line to the throne of Monaco, to Colombian heiress Tatiana Santo Domingo was a royal wedding in all but name – and one of which Mr Casiraghi's grandmother Grace Kelly would have been proud.
The ceremony was held within the walls of the Prince's Palace, an ornately decorated fortress originally built by the Genoese in 1215.
After their vows, taken in the shade of the palm trees overlooking Monaco's marina, the couple hosted an al fresco poolside lunch for their 350 guests.
Two days ahead of the wedding, Lauren Santo Domingo, Tatiana's aunt and a contributing editor to American Vogue, posted a photo on social media of the bride-to-be and her friends.
The group, who included the fashion designer Margherita Missoni, 30; Noor Fares, 27, a Lebanese jewellery designer, and scion of the Greek shipping family Eugenie Niarchos, 27, all posed on the deck of Princess Caroline of Monaco's yatch, the Pacha III.