Pietro (Petru in Corsican) Rocca was a writer and contributed in Corsica to the magazine A Tramuntana. During World War I he wrote about the war and was decorated with the French Legion of Honor.
Since May 1920 Rocca worked with the literary magazine A Muvra, and in 1922 he created the Partitu Corsu d'Azione, following the model of the Italian Partito Sardo d'Azione of Sardinia that had autonomism ideals.
He successively created in the late 1920s the "Partito autonomista di Corsica" (of which was segretary) with the support of monsignor Domenico Parlotti and dr. Croce, director of the "Archivi di Stato della Corsica".
During the late 1930s Rocca slowly changed his political opinions from the autonomism for his Corsica to the Italian irredentism ideals, supporting the union of Corsica to Italy. In those years he had political & literary relationship with Petru Giovacchini, Marco Angeli di Sartèna,
Marta Renucci and other writers supporting this irredentism. In 1938, the French government punished him, because of his approach to the Italian Risorgimento ideals, eliminating his "Ordre de la légion d'honneur": "A Muvra" started in 1939 to write articles against the Jews (responsible in Rocca's opinion for the French "occupation" of Corsica) and was quickly closed.
During World War II Rocca supported Benito Mussolini's ideals about the union of Corsica to the Kingdom of Italy and as a consequence in 1946 was sentenced to 15 years of jail and sent to the French Guiana (Devil's Island)). When released, he quickly recreated his original "Partito autonomista di Corsica".
In 1953, Petru Rocca created an academy for the defense of the Corsican language and demanded from France the acceptance of the Corsican people and language and the creation of the University of Corte. Rocca was, until his death in 1966, a strong supporter of Corsican nationalism.