| Castelsardo | |
| Official Name: | Comune di Castelsardo |
| Pushpin Map: | Italy Sardinia |
| Coordinates: | 40.9167°N 51°W |
| Region: | Sardinia |
| Province: | Sassari (SS) |
| Frazioni: | Lu Bagnu, [lMulteddu, San Giovanni, Terra Bianca, Pedra Sciolta, Lu Romasinu, Punta Tramontana | mayor_party = | mayor = Maria Lucia Tirotto | area_footnotes = | area_total_km2 = 43.34 | population_footnotes = | population_total = 5610 | population_as_of = 2022 | pop_density_footnotes = | population_demonym = Castellanesi | elevation_footnotes = | elevation_m = 114 |istat=| saint =St. Antony | day =17 January (17/01) | postal_code = 07031 | area_code = 079 | website ={{official website|http://www.comune.castelsardo.ss.it/}} | footnotes = ] |
Castelsardo (Castheddu; Castellanese : Calteddu; Sardinian: Casteddu Sardu) is a town and comune in Sardinia, Italy, located in the northwest of the island within the Province of Sassari, at the east end of the Gulf of Asinara. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy").[1]
Archaeological excavations have showed the human presence in the area of Castelsardo since pre-Nuragic and Nuragic times, as well as during the Roman domination in Sardinia.
After the fall of the Western Roman Empire, the monastery of Nostra Signora di Tergu was founded nearby, but the current town originates from the castle built here, in 1102 (or 1270), by the Doria family of Genoa. The castle and the village which gradually formed round it where the seat of the Doria's fiefdom in the island called Castel Doria or Castelgenovese, until it was conquered by the Aragonese in the 15th century (1448), and named Castillo Aragonés (Castel Aragonese). Except for the Maddalena archipelago, it was the last city in the island to join the Kingdom of Sardinia.
Castelsardo, was part of the Savoy's Kingdom of Sardinia, obtained by will of King Charles Emmanuel III.
«Title of 1448 issued by the crown of Aragon»