The Royal Alcázar of Seville is Europe's oldest royal palace still in continuous use, founded in 913 AD and standing as a UNESCO World Heritage masterpiece. Originally constructed as a Moorish fortress and rebuilt as a royal residence during the 14th century by Peter the Cruel, the palace exemplifies the sophisticated blend of Islamic, Gothic, Renaissance, and Baroque architectural styles that define Mudéjar art. Its intricate arches, lush courtyards, and ornate decorations reflect centuries of cultural synthesis, while its ongoing use by the Spanish royal family as their official Seville residence underscores its enduring significance in Spain's historical and political landscape.