Not a formal organization, it was rather an opinion movement that claimed that Italy had to reach its 'natural borders'. Similar patriotic and nationalistic ideas were common in Europe in the 19th century. The term 'irredentism' was successfully coined from the Italian word in many countries in the world (List of irredentist claims or disputes). This idea of 'Italia irredenta' is not to be confused with the Risorgimento, which was the historical events that led to irredentism, or with Greater Italy, which was the political philosophy that took the idea further under Fascism.
After the Italian unification of 1861, there were areas with Italian peoples in several countries around the newly created Kingdom of Italy. The Irredentists sought to annexe all those areas into a single Italy, including some areas with a non-Italian majority. The areas targeted were Corsica, Dalmatia, Gorizia and Gradisca, the Ionian islands, Istria, Malta, Nice, Ticino, Trentino, Trieste and Rijeka.
Initially, the movement can be understood as part of a more general nation-building process in Europe in the 19th and 20th centuries when the multi-national Austro-Hungarian, Russian, and Ottoman Empires were being replaced by nation states. The Italian nation-building process can be compared to similar movements in Germany (Großdeutschland), Hungary, Serbia, and in pre-1914 Poland. Simultaneously, however, in many parts of 19th century Europe, liberalism and nationalism were ideologies which were coming to the forefront of political culture. In Eastern Europe, where the Habsburg Empire had long asserted control over a variety of ethnic and cultural groups, nationalism appeared in a standard format. The beginning of the 19th century, "was the period when the smaller, mostly Slavic nationalities of the empire - Czechs, Slovaks, Slovenes, Croats, Serbs, Ukrainians, and the Latin Romanians - remembered their historical traditions, revived their native tongues as literary languages, reappropriated their traditions and folklore, in short reasserted their existence as nations. The notion of a single united Italy ran counter to the aspirations of the majority populations.
One of the first 'Irredentists' was Giuseppe Garibaldi who, in 1859 as deputy for his native Nice in the Piedmontese parliament at Turin, attacked Cavour for ceding Nice to Napoleon III in order to get French help and approval for Italian Unification. Irredentism grew in importance in Italy in the next years.
On July 21, 1878, a noisy public meeting was held at Rome with Menotti Garibaldi, the son of unification leader Giuseppe Garibaldi, as chairman of the forum, and a clamour was raised for the formation of volunteer battalions to conquer the Trentino. Benedetto Cairoli, then Prime Minister of Italy, treated the agitation with tolerance.
It was, however, mainly superficial, as most Italians had no wish to launch a dangerous policy of adventure against Austria, and still less to attack France for the sake of Nice and Corsica, or Britain for Malta.
One consequence of Irredentist ideas outside of Italy was an assassination plot organized against the Emperor Francis Joseph in Trieste in 1882, which was detected and foiled. Guglielmo Oberdan, a Triestine and thus Austrian citizen, was executed. When the Irredentist movement became troublesome to Italy through the activity of Republicans and Socialists, it was subject to effective police control by Agostino Depretis.
Irredentism faced a setback when the French occupation of Tunisia in 1881 started a crisis in French–Italian relations. The government entered into relations with Austria and Germany, which took shape with the formation of the Triple Alliance in 1882.
The Irridentists' dream of absorbing the targeted areas into Italy made no further progress in the 19th century, as the borders of the Kingdom of Italy remained unchanged and the Rome government began to set up colonies in Eritrea and Somalia in Africa.
Italy signed the London Pact and entered World War I with the intention of gaining those territories perceived by Irridentists as being Italian under foreign rule. According to the pact, Italy was to leave the Triple Alliance and join the Entente Powers. Furthermore, Italy was to declare war on Germany and Austria-Hungary within a month. The declaration of war was duly published on 23 May 1915 . In exchange, Italy was to obtain various territorial gains at the end of the war. In April 1918, in what he described as an open letter "to the American Nation" Paolo Thaon di Revel, Commander in Chief of the Italian navy, appealed to the people of the United States to support Italian territorial claims over Trento, Trieste, Istria, Dalmatia and the Adriatic, writing that "we are fighting to expel an intruder from our home" . The outcome of the First World War and the consequent settlement of the Treaty of Saint-Germain met some Italian claims, including many (but not all) of the aims of the Italia irredenta party . Italy gained Trieste, Gorizia, Istria and the cities of Rijeka and Zadar. In Dalmatia, despite the Treaty of London, only Zadar with some Dalmatian islands such as Cres, Lošinj and Lastovo were annexed by Italy, as Woodrow Wilson, supporting Slavic claims and not recognizing the treaty, rejected Italian requests on other Dalmatian territories..
The stand taken by Gabriele D'Annunzio, which briefly led him to become an enemy of the Italian state , was meant to provoke a nationalist revival through Corporatism (first instituted during his rule over Rijeka), in front of what was widely perceived as state corruption engineered by governments such as Giovanni Giolitti's. D'Annunzio briefly annexed to this "Regency of Carnaro" the Dalmatian islands of Krk and Rab where there was a numerous Italian community.
In 1922 Mussolini temporarily occupied Corfu, perhaps using irredentist claims based on minorities of Italians in the Ionian islands of Greece. Similar tactics may have been used towards the islands around the Kingdom of Italy - through the Maltese Italians, Corfiot Italians and Corsican Italians - in order to control the Mediterranean sea (that he called in Latin Mare Nostrum).
Around 1939, the main territories sought included the rest of Istria, more of Dalmatia, the Ionian Islands (in Greece), Malta, Corsica, Nice, Savoy and Ticino. Other claims were also made for the Fourth Shore, which meant coastal Libya and Tunisia, and The Dodecanese islands of the Aegean Sea.
During World War II, large parts of Dalmatia were annexed by Italy into the Governorship of Dalmatia from 1941 to 1943. Corsica and Nice were also administratively annexed by the Kingdom of Italy in November 1942. Malta was heavily bombed but was not occupied, due to Allied naval control of the Mediterranean and the success of Operation Pedestal, one of the most important British strategic victories of the Second World War.
After Italian capitulation in 1943, areas formerly under Italian control in Istria and the Julian March were controlled by Yugoslav Partisans. Shortly afterwards these areas were occupied by the German Wehrmacht and SS forces that brutally suppressed the Partisans, especially on the Istrian peninsula.
After 1945, many Italians chose to move to Italy, and there was a significant decline in Italian speaking populations in Istria and Dalmatia.
Italian irredentists, like the fascist Gabriele D'Annunzio, claim that Joseph Fölch allegedly overlooked the Dalmatian islands of Cres, Lošinj, Vis and others with significant Italian communities, and that the only official evidence about the Dalmatian population comes from the 1857 Austro-Hungarian census, which showed that in this year there were 369,310 Slavs and 45,000 Italians in Dalmatia, making Dalmatian Italians 15% of the total population of Dalmatia in the mid-19th century.
The last city with a significant Italian presence in Dalmatia was Zadar. In the Austro-Hungarian census of 1910 Zadar had an Italian population of 9,318 (or 69.3% of the total of 13,438 inhabitants). Zadar's population grew to 24,100 inhabitants, of whom 20,300 were Italians,, while in 1942 it was designated as the capital of Italian-occupied Yugoslavia (Governorship of Dalmatia). Many of the local population were killed or injured in the bombing of Zadar by Allied air forces in 1943 and 1944. Some Italian sources claim that the city was destroyed for political reasons: it was bombed because of alleged incorrect information that was supplied to the Allies by Marshal Josip Broz Tito's Partisans. Italians also claim that their intent was to clear out the only remaining Italian enclave in Dalmatia.
On the other hand, sources point out that Zadar, situated on a peninsula, was surrounded by the primary port facilities of the Italian occupation forces, and, as a result, the city center was surrounded by potential targets. A bomber unit of the period had little or no capability at such precision bombing that would completely spare the city center but still destroy the adjoining military naval facilities. Apart from all this, Zadar was also located on the flight route of Allied planes flying from southern Italy to targets in central Europe. With the 1947 Peace Treaty, Italians still living in Zadar - no more than three thousand - were granted the opportunity to become Italian citizens as an alternative to Yugoslav citizenship, but with the obligation to take up residence in Italy. About 100 Italians remain in the city today.
Some Croatian and Slovenian politicians and organizations (supported by some politicians from their countries) assert that Italy - in their opinion - openly propagates irredentist ideas even in the 21st century, often causing sharp reactions from Croatian and Slovenian officials.
They often cite the Italian Deputy Prime Minister Gianfranco Fini, who in Senigallia in 2004 gave an interview to the Slobodna Dalmacija daily newspaper at the 51st gathering of the Italians who left Yugoslavia after WWII, in which he was reported to have said that "From the son of an Italian from Fiume I learned that those areas were and are Italian, but not because at any particular historical moment our army planted Italians there. This country was Venetian, and before that Roman" . Rather than issuing an official rebuttal of those words, Carlo Giovanardi, Parliamentary Affairs Minister in Berlusconi's government, affirmed Fini's words, saying "...that he told the truth"..
These sources point out that on the 52nd gathering of the same association, in 2005, Carlo Giovanardi was quoted by the Večernji list daily newspaper as saying that Italy would launch a cultural, economic and tourist invasion in order to restore "the Italianness of Dalmatia" while participating in a round table discussion on the topic "Italy and Dalmatia today and tomorrow" . Giovanardi later declared that he had been misunderstood , and sent a letter to the Croatian Ministry of Foreign Affairs in which he condemned nationalism and ethnic strife .
They underline that Alleanza Nazionale, an Italian conservative party, derives directly from the Italian Social Movement (MSI), a neo-fascist party, which often claimed that Italy paid too much for her defeat in WWII, repeating that "Dalmatia was stolen from Italy". For example, in 1994, Mirko Tremaglia, a member of the MSI and later of Alleanza Nazionale, described Rijeka, Istria and Dalmatia as "historically Italian" and referred to them as "occupied territories", saying that Italy should "tear up" the 1975 Treaty of Osimo with the former Yugoslavia and block Slovenia and Croatia's accession to EU membership until the rights of their Italian minorities are respected.
Croatian authorities believe that the threat of this "contemporary irredentism" may be clearly seen by the proposed issue of stamps related to Rijeka, a previously Italian city in the Adriatic called Fiume in Italian. In 2007, the Italian Post Office printed 3,000,000 copies of a stamp with a 1922 photo of Rijeka, when its official name was Fiume, with the text Fiume - terra orientale già italiana (Rijeka - eastern land formerly Italian.) . The Croatian Foreign Ministry sent a protest note to Italy, saying it had "informed Italy that the content was unacceptable" . Following the protests, the release of the stamp was postponed until the end of the year. In the Croatian city of Poreč, Italian irridentist graffiti has periodically been appearing.