Caroline, Princess of Hanover Caroline, Princess of Hanover Caroline, Princess of Hanover (Caroline Louise Marguerite Grimaldi; born 23 January 1957), is the eldest child of Rainier III, Prince of Monaco, and the American actress Grace Kelly. She is the elder sister of Prince Albert II and Princess Stéphanie. Until the births of her niece and nephew, Princess Gabriella and Prince Jacques, in December 2014 she had been heir presumptive to the throne of Monaco since 2005, a position which she previously held from 1957 to 1958. Caroline is married to Ernst August, Prince of Hanover (born 1954), the heir to the former throne of
Rainier III, Prince of Monaco Onassis, who took control of the Société des Bains de Mer (SBM) and envisioned Monaco as solely a gambling resort. Prince Rainier regained control of SBM in 1964, effectively ensuring that his vision of Monaco would be implemented. In addition, the Societé Monégasque de Banques et de Métaux Précieux, a bank which held a significant amount of Monaco's capital, was bankrupted by its investments in a media company in 1955, leading to the resignation of Monaco's cabinet. As Prince of Monaco, Rainier was also responsible for the principality's new constitution in 1962 which significantly reduced the power of the sovereign.