Four centuries of history of the Duchy of Mandas are preserved in the Spanish archives. The sensational discovery was made by the mayor of the town in the upper Trexenta region, Umberto Oppus, who for five days donned his archivist's smock and swathed his tricolor sash to delve into the 120 folders of the Historical Archive of the Nobles of Toledo, Spain, dedicated to the period of Spanish rule over the island. Oppus's unique vacation allowed him to bring back 700 photocopied pages to Mandas to study and analyze, rewriting part of the history of the ancient fiefdom of Mandas, famous for being the only Spanish Duchy in Sardinia, granted in 1350 to Giovanni Carròz, a member of a powerful Valencian family who had aided the King of Aragon during the conquest of Sardinia.

The Duchy, which existed until 1843, encompassed a vast territory that included the Curatoria of Siurgus, the Barbagia of Seulo, the Barbagia of Ollolai, the Barony of Sicci, and the Marquisate of Terranova. Its administrative center was in the town of Mandas. A veritable goldmine for delving into the history of a vast territory with a glorious past. "Together with the archivists of Toledo, I was able to delve into the history of the 25 towns of the Duchy of Mandas," says Oppus. "Over 100 folders containing 20,000 documents on our past. From Fonni to Ovodda, from Lodine to Sarule, passing through Gavoi, Mamoiada, Orani, Orgosolo, and Olzai: a constant flow of documents and precious information." A castle of papers and documents to study and reconstruct.