d'Italia suffix was added to the name of Campione in the 1930s by Prime Minister Benito Mussolini and an ornamental gate to the city was built, both in an attempt to assert the exclave's Italian-ness. There remained some territorial disputes after the formation of the Kingdom of Italy, resolved in the Convenzione tra l'Italia e la Svizzera per l'accertamento della frontiera fra la Lombardia ed il Cantone dei Grigioni of 1863. Since then, the international borders of Switzerland have been undisputed and, except for minor corrections, unchanged (the internal borders of the cantons of Switzerland have been subject to revision, mostly in the context of the Jura question). Further Swiss-Italian treaties regarding the course of the border date to 1873/4, 1936/7 and 1941. The part of the Chablais region south of Lake Geneva was ceded to the Kingdom of Sardinia by the Congress of Vienna, but declared a demilitarized zone, and Switzerland was granted the right to occupy both Chablais and Faucigny for its own protection in the case of war. In 1860, when France annexed Savoy from the Kingdom of Piedmont-Sardinia, Napoleon III declared his intention to cede Chablais and Faucigny to Switzerland, but later reneged on the promise. The Swiss authorities were themselves ambivalent on the matter, as they feared the destabilising effect the annexation of two Catholic provinces might have on interfaith relations within the country. But popular opinion in Switzerland was outraged at Napoleon's breach of promise. Switzerland increased its military presence at the southern border to prevent clashes between Savoyard and Swiss irregulars. The crisis subsided gradually as it became clear that Napoleon adhered to the promise of neutrality for Haute-Savoie renewed in the Treaty of Turin of 24 March 1860. But Switzerland did not recognize the annexation of Savoy, and the status of Chablais was brought before the Permanent Court of International Justice several times between 1922 and 1932. In 1918 after the First World War, a referendum was held in the small exclave Büsingen am Hochrhein in Baden-Württemberg in which 96% of voters chose to become part of Switzerland. However the change of country never took place as Switzerland could not offer anything suitable in exchange and consequently, Büsingen has remained an exclave of Germany ever since. Later attempts to transfer Büsingen to Switzerland were also unsuccessful. The status of the municipality of Büsingen was however formally defined in 1967 through negotiations between