History of Sardinia
In the Early Middle Ages, through barbarian movements, the waning of the Byzantine Empire influence in the western Mediterranean and the Saracen raids, the island fell out of the sphere of influence of any higher government. This led to the birth of four kingdoms called "Judicates" (Latin: "Judicati"; Sardinian: "Judicados") in the 8th through 10th centuries. Falling under papal influence, Sardinia became the focus of the rivalry of Genoa and Pisa, the Judicates and the Crown of Aragon, which eventually subsumed the island as the Kingdom of Sardinia in 1324. The Kingdom was to last until 1718, when it was ceded to the Piedmontese House of Savoy; later, in 1861, it would thus become the Kingdom of Italy and finally in 1946 the Italian Republic.
Sardinian nationalism
Sardism, which had long been confined to the island's intellectuals, made its political debut for the first time in the occasion of Ireland's independence (1921) with the Sardinian Action Party or PSd'Az (one of the oldest parties in Europe advocating for regional self-determination,), which got 36% of the popular vote in 1921 regional election. Sardinian nationalism thus established itself as the most important mass movement in Sardinia, and the Psd'Az a political force that Mussolini had to reckon with and eventually ban in 1926; some Sardists, like Emilio Lussu, were forced into hiding and participated in the main European fronts of anti-fascism (like Dino Giacobbe and Giuseppe Zuddas in the Spanish Civil War), while others decided to join the Fascist Party, hoping that by adhering to the regime Sardinia would get autonomy in exchange (a demand facing an immediate rejection) or at least some attention from the Mainland (which they eventually got through some moderate funding concentrated in Cagliari for the local infrastructures). Overall, rural Sardinia showed little interest in the Fascist state, let alone consent, while the bourgeois segments from the urban settlements were among the staunchest supporters of the regime on the island. Following the Second World War, the Psd'Az, already weakened by the loss of many of its key members during the conflict, suffered a first split between the moderate wing and a much more radical one, led by Sebastiano Pirisi, which developed into another party ("Lega Sarda", "Sardinian League") but ultimately got poor results in the 1946 Italian general election.