The town of Castelsardo originates from the castle built in the 12th or 13th century 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). Later it became the seat of the bishopric until the Cathedral of Sant’Antonio Abate was built in 1586.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.