Italianization of names was encouraged by the Italian authorities. The islanders did, however, not receive full citizenship and were not required to serve in the Italian armed forces. The population was allowed to elect their own mayors. Lagos' successor, Cesare Maria De Vecchi, embarked on a forced Italianization campaign in 1936. The Italian language became compulsory in education and the public life, with Greek being only an optional subject in schools. In 1937 the elected mayors were replaced by appointed loyal fascists. In 1938, the new Italian Racial Laws were introduced to the islands. South Tyrol In 1919, at the time of its annexation, the southern part of Tyrol was inhabited by almost 90% German speakers. In October 1923, the use of the Italian language became mandatory (although not exclusive) on all levels of federal, provincial and local government. Regulations by the fascist authorities required that all kinds of signs and public notices be in Italian only. Maps, postcards and other graphic material had to show Italian place names. In September 1925, Italian became the sole permissible language in courts of law. Illegal Katakombenschulen ("Catacomb schools") were set up by the local German-speaking majority to teach children the German language. The government created incentives to encourage immigration of native Italians to South Tyrol. Several factors limited the effects of the Italian policy, namely the adverse nature of the territory (mainly mountains and valleys of difficult access), the difficulty for the Italian-speaking individuals to adapt to a completely different environment and, later on, the alliance between Germany and Italy: under the 1939 South Tyrol Option Agreement, Adolf Hitler and Benito Mussolini determined the status of the German people living in the province. They either had to opt for emigration to Germany or stay in Italy and become fully Italianized. Because of the outbreak of World War II, this agreement was never fully implemented and most ethnic Germans remained or returned at the end of the war. Following World War II, South Tyrol was one of the first regions to be granted autonomy on the ground of its peculiar linguistic situation; any further attempts at Italianization were formally abandoned. In the 21st century, just over 100 years after the Italian annexation of the region, 64% of the population of South Tyrol speak German as their first and everyday language. Sardinia In 1720, the island of Sardinia was ceded to Alpine House of