While he was Hereditary Prince, Charles was married on 28 September 1846 in Brussels to Countess Antoinette de Mérode-Westerloo. He succeeded his father Prince Florestan I in 1856. During his reign, the towns of Menton and Roquebrune, constituting some 80 percent of Monegasque territory, were formally ceded to France, paving the way for formal French recognition of Monaco's independence. Rebellions in these towns, aided by the Kingdom of Sardinia, had exhausted Monaco's military resources for decades. The Principality was in dire need of cash flow, so Prince Charles and his mother, Princess Caroline, had the idea of erecting a casino. The Monte Carlo Casino was done, according to the Prince's liking, in the German style and placed at the sight of Les Spélugues. Monte Carlo itself takes its name from Charles, after all its founder. Charles established a society to run the Casino; this society is today the Société des bains de mer de Monaco. Under Charles III, the Principality of Monaco increased its diplomatic activities; for example, in 1864, Charles III concluded a Treaty of Friendship with the Bey of Tunis, Muhammad III as-Sadiq, which also regulated trade and maritime issues.
Honours
is named after Charles III. It stands for the "Mount Charles" in Italian. The Order of Saint-Charles was instituted on 15 March 1858, during the reign of Prince Charles III. He received the following decorations and awards:
Grand Cross of St. Olav, with Collar, 27 March 1863
In his middle years his sight greatly weakened, and by the last decade of his life he had become almost totally blind. In fact, Dr. Thomas Henry Pickering wrote in 1882: "So far back as 1860, Prince Charles lost his eyesight...." He died at Château de Marchais on 10 September 1889. He was succeeded by his son Albert I of Monaco.
Coin
On 1 June 2016, fifteen thousand 2 euro coins were issued by Monaco; commemorating the 150th anniversary of the foundation of Monte Carlo by Charles III
In literature
Charles III is referenced, as Prince Charles Honoré, in a fictional entitled, The Fall of Prince Florestan of Monaco, by the British politician Sir Charles Wentworth Dilke. This work was one of satire and parody on a number of political characters of the day. It centered around a Cambridge-educated, half-Württemberg nephew of Charles III who comes to the throne by way of Charles III and the next two heirs being wiped out of existence. The upstart "Florestan II", a radical republican, boldly attempts to democratize Monaco. He fails and then is forced to leave the country.
