The ducal palace, Schloss Celle, whose foundations date to the 13th century, is the oldest building in the town. What started as a castle for the dukes of Lüneburg, fortified with moats and ramparts, was gradually expanded and modified into a mixture of Baroque and Renaissance architecture. From 1772 it was home to the British-born, Danish queen, Caroline Matilda, the daughter of Frederick, Prince of Wales, who had been banished to Celle as a result of her affair with Johann Friedrich Struensee of Copenhagen. She only lived at the Celle court until 1775 when she died at 23 of scarlet fever. In the 19th century the castle was occasionally used by the Hanoverian royal household as a summer residence. Guided tours visit the Renaissance chapel, Baroque theatre, ducal chambers and palace kitchen.