occupied by Germany, which reorganised it as the Operation Zone of the Alpine Foothills and put it under the administration of Gauleiter Franz Hofer. The region was de facto annexed to the German Reich (with the addition of the province of Belluno) until the end of the war. This status ended along with the Nazi regime and Italian rule was restored in 1945. Italy and Austria negotiated the Gruber-De Gasperi Agreement in 1946, put into effect in 1947 when the new republican Italian constitution was promulgated, that the region would be granted considerable autonomy. German and Italian were both made official languages, and German-language education was permitted once more. The region was called Trentino-Alto Adige/Tiroler Etschland between 1947 and 1972. However, the implementation of the agreement was not seen as satisfactory by neither the German-speaking population nor the Austrian government. The issue became the cause of significant friction between the two countries and was taken up by the United Nations in 1960. A fresh round of negotiations took place in 1961 but proved unsuccessful, partly because of popular discontent and a campaign of terrorism and bombings by German-speaking autonomists and separatists led by the South Tyrolean Liberation Committee. The issue was resolved in 1971, when a new Austro-Italian treaty was signed and ratified. It stipulated that disputes in South Tyrol would be submitted for settlement to the International Court of Justice in The Hague, that the province would receive greater autonomy within Italy, and that Austria would not interfere in South Tyrol's internal affairs. The new agreement proved broadly satisfactory to the parties involved and the separatist tensions soon eased. Matters were helped further by Austria's accession to the European Union in 1995, which has helped to improve cross-border cooperation. In May 2006, senator-for-life Francesco Cossiga introduced a bill that would allow the region to hold a referendum, in which the local electorate could decide whether to stay within the Italian Republic, become fully independent or return to Austria. All parties, including the separatists, rejected this measure as potentially causing a revival of ethnic tensions. Geography The region is bordered by East and North Tyrol (Austria) to the north-east and north respectively, by Graubünden (Switzerland) to the north-west, and by the Italian regions of Lombardy to the west and Veneto to the south and south-east. It covers . It is extremely mountainous, covering a large part of the Dolomites and