By November 25, 1847, the deteriorating situation forced the Grimaldi family to request military intervention from the Royal Sardinian Army to restore order to the two cities.

On March 21, the provisional government officially declared their independence as the Free Cities of Menton and Roquebrune and made its own version of the Italian Tricolor.

[3] King Charles Albert of Sardinia, who had recently begun the First Italian War of Independence, accepted the new protectorate status of Menton and Roquebrune, moving in troops on 3 April.

By 18 September Charles Albert declared the cities temporarily under the protection of Sardinia, implementing Sardinian law and the Albertine Statute.

Treca resigned his position as president on April 30 1849, with Sardinian authorities officially annexing the free cities into the kingdom, coming under the administration of the County of Nice.