Risorgimento, then two years later placed themselves under the protection of the Kingdom of Sardinia where they were administered by the House of Savoy for ten years.
The Treaty of Turin concluded on 24 March 1860 between the Kingdom of Sardinia and Napoleon III's France called for the annexation of the County of Nice to France, subject to a plebiscite, as a reward for French assistance in Italy's war against Austria. The plebiscite, with universal adult male suffrage, was held on April 15 and 16, 1860 and resulted in an overwhelming vote in favor of annexation (833 for vs 54 against in Menton and Roquebrune),despite complaints of rigged elections from, among others, Nice-born Italian nationalist Giuseppe Garibaldi. The county of Nice was thus annexed to France that June, and Napoleon III paid 4 million francs in compensation to the prince of Monaco, who renounced his rights in perpetuity on 2 February 1861.
From the end of the 19th century, tourism became an important factor in Menton. The town was popular with English and Russian aristocrats who built many of the luxurious hotels, villas, and palaces which still grace Menton today. Many of these hotels and palaces were pressed into service as hospitals during World War I to allow injured troops to recuperate in a pleasant climate.
Menton was the only sizable settlement captured by Italy during its invasion of France in June 1940. Following the armistice of June 22, 1940, two thirds of the territory of the commune was annexed by Italy as "terra irredenta". The annexation lasted until 8 September 1943.
Although officially returned to Vichy France, Menton was in fact occupied by Nazi Germany until its liberation by American and Canadian troops of the First Special Service Force on 8 September 1944
