Franco-Monegasque Treaty

The Franco-Monégasque Treaties of 1861, 1918 and 2002 are the basis of the relationship between France and the Principality of Monaco. The treaties define Monaco's independent status and sovereignty, as well as the rights of succession of the princely House of Grimaldi.

The Franco-Monégasque Treaty of 1861 recognised the sovereignty of Monaco. Previously, under the Treaty of Vienna, the principality had been a protectorate of the Kingdom of Sardinia.

A second treaty was agreed on July 17, 1918, owing to the Monaco Succession Crisis of 1918 near the end of the First World War. At the time the heir to the Monégasque throne had no legitimate children, and the possibility of his German cousins, the Dukes of Urach, succeeding in the future to the throne was unacceptable to the French. Pressure was brought to bear on the Monégasques to ratify treaty provisions which would empower France to prevent such an occurrence.

A third treaty was signed on October 24, 2002. The new treaty addressed issues of sovereignty raised by the 2002 revision of Monaco's constitution. Under those constitutional revisions, approved by the 2002 treaty, although only a born member of the Grimaldi line may now wear the Crown, Monaco assumes the unilateral prerogative to alter the order of succession and the principality's independence is explicitly secured. This resolved Monégasque concerns that under the 1918 treaty dynastic acts affecting the succession (such as marriage or adoption within the reigning House of Grimaldi) required French assent, yet if a vacancy on the throne occurred, Monaco would have automatically become a French protectorate. That prospect no longer exists.

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