Dashing blue blood Andrea Casiraghi may be fourth in line for the throne of Monaco - one of the wealthiest countries in the world - but it seems his wife Tatiana Casiraghi (née Santo Domingo) has amassed an even greater fortune. Mrs Casiraghi, 31, who wed her 30-year-old husband in 2013, just landed herself on Forbes' 2015 World's Billionaires list at number 847, with an estimated net worth of $2.2billion, which she largely inherited from her Bavaria beer brewery owner grandfather, Julio Mario Santo Domingo, in 2011. The socialite couple currently reside in Paris with their son Sasha, who turns two this month, and Mrs Casiraghi is approximately four months pregnant with their second child. Scroll down for video . Power couple: Tatiana Casiraghi, 31, (right) who wed her 30-year-old husband Andrea Casiraghi (left) in 2013, made Forbes' 2015 World's Billionaires list at number 847, with an estimated net worth of $2.2 billion . Mr Casiraghi - the eldest son of Princess Caroline and her second husband Stefano Casiraghi, and the eldest grandson of Rainier III, Prince of Monaco, and American actress Grace Kelly - did not appear on Forbes' rich list. Though his net worth is unknown, his looks have earned him plenty of credit over the years. The blonde aristocrat made Forbes' 20 Hottest Young Royals list in 2008, and was named the second most beautiful male royal of all time by BeautifulPeople in 2011. Mrs Casiraghi was born in New York and raised between Geneva, Switzerland, and Paris. Her grandfather was cited the second richest man in Colombia by Forbes in 2011, and died the same year at the age of 87. Heirs: Mrs Casiraghi - pictured (left) with her 23-month-old son Sasha, as well as her husband (right) in November - inherited her fortune from her Bavaria  brewery owner grandfather, Julio Mario Santo Domingo, in 2011 . Welcome! Mr and Mrs Casiraghi waited a year and a half to publicly introduce Sasha to the world, which they did at Monaco's National Day celebrations at the Palais Princier de Monaco (pictured) on November 19 . In his will, Domingo split his vast $8 billion fortune six ways between his children and grandchildren; leaving Mrs Casiraghi and her New York-based DJ brother, Julio Mario Santo Domingo III, an equal share of $2 billion. Mrs Casiraghi, who founded an ethical fashion retailer called Muzungu Sisters in 2011, met her husband while the two were at boarding school together in Fontainebleau, near Paris. They dated for seven years before tying the knot in a civil ceremony in Monaco on August 31, 2013. The pair later hosted a second celebration in Gstaad, Switzerland on February 1, where they exchanged their vows in a candlelit Roman Catholic service. In addition to their son, the ceremony was attended by a number of their close family and friends, including Princess Caroline, Prince Albert and the groom's siblings, Pierre, Charlotte and Alexandra. Baby bump: Mrs Casiraghi, pictured at Paris Fashion Week on January 26, resides in Paris with her husband and son, and is approximately four months pregnant with the couple's second child . Busy: The heiress, pictured in Paris in January, founded an ethical fashion retailer called Muzungu Sisters in 2011 and dedicates much of her spare time to charity work . Longtime loves: The pair, pictured at the Monaco National Day Gala in November, met when they were at boarding school together in Fontainebleau, near Paris . Society darlings: They dated for seven years before tying the knot in a civil ceremony in Monaco on August 31, 2013. Pictured, the couple in September at a friend's wedding ceremony in Germany . Mr and Mrs Casiraghi, who, in addition to carrying out their royal duties, both support a number of children's charities and a cerebral palsy fund called the Motrice Foundation, waited a year and a half to publicly introduce their son Sasha to the world. In November of last year, they appeared with him at Monaco's National Day celebrations at the Palais Princier de Monaco alongside the rest of the royal family, including Prince Albert and his then-pregnant wife Charlene. Princess Charlene, 39, gave birth to twins Gabriella and Jacques on December 12.
Andrea Casiraghi, 30, is the eldest son of Princess Caroline and her second husband, the late Stefano Casiraghi . He is currently fourth in line for the throne of Monaco . Tatiana Casiraghi (née Santo Domingo) made Forbes' 2015 World's Billionaires list at number 847 . The 31-year-old socialite inherited $2billion from her grandfather Julio Mario Santo Domingo, former owner of the Bavaria beer brewery, in 2011 . Mr and Mrs Casiraghi, who wed in 2013, have a son, Sasha, who turns two this month, and are expecting their second child this summer .