One of the longest reigning monarchs was born in Monaco, the only son of Prince Pierre of Monaco, Duke of Valentinois. His birth date was May 31, 1923 and he became ruler upon the death of his father. Rainier Louis Henri Maxence Bertrand Grimaldi was known for marrying Grace Kelly, reforming Monaco's constitution and expanding Monaco's economy.
Rainier worked hard to bring back Monaco's reputation which had fallen due to scandals and neglect. Rainier promoted Monaco as a tax haven, commercial center, international tourist attraction and real-estate development opportunity. He was also responsible for the constitution changes in 1962 that significantly reduced the power of the sovereign. These changes ended autocratic rule and placed power with the prince and the National Council.
Prince Rainier was married to Grace Kelly, an Oscar winning actress, from 1956 until her death in 1982. They had three children and their son Albert was designated as heir apparent.
Rainier suffered from coronary problems as well as a lung infection. He was in the hospital intensive care unit and placed on a ventilator shortly before his death. His son, Prince Albert took over Rainier's duties in April of 2005 and the Prince died on April 6, 2005.