The “day of the sovereign” is traditionally set on the day of the patron saint of the Reigning Prince. However, Prince Rainier III broke from from this tradition by choosing the day of his coronation, 19 November, which is the same day the blessed Rainier d’Arezzo is also celebrated. In memory of his father, Prince Albert II has kept the same date, thus fixing the day of the Monégasque National Holiday.

Prince Charles III began the tradition, at the time when the Principality became a modern and independent state with its national flag, diplomatic representation abroad and treaties signed with various powers. Dating back to 1857, the second year of his reign, Charles III decided that the 4th of November, the feast day of his patron saint, should be declared “Feast of the Sovereign”.

During his reign, the Sovereign’s patronal feast, called “Feast of the Prince” by the Monégasques, was celebrated with a Te Deum in the church of Saint-Nicolas. In 1871, after the Te Deum, the first military parade took place in the Palace Square with the Prince’s Guards Company. In addition, there were several celebrations, including: a big fireworks display, concerts and popular games on the Rock. However, it was not until 1875 that the Carabinieri, members of the Italian national police force, participated in the event.

After his death on 10 September 1889, by the Sovereign Order of 8 May 1890, Prince Albert I fixed “Prince’s Day” as 15 November, St Albert’s Day. After Prince Rainier III’s ascension to the throne on 19 November 1949, another Sovereign Order was adopted setting the date to 19 November.