Most English country houses, like Chatsworth, were built between the 17th and 18th centuries by the aristocracy to impress and attract royalty.  The Duke of Devonshire explains that Chatsworth's immense size reflects its purpose: to house and entertain visiting monarchs.  A magnificent suite, built in 1686 for King William and Queen Mary, remained unused by them, though Edward VII visited frequently (1901-1910) and George V and Queen Mary visited in 1913.  The Cavendish family, who owned Chatsworth, held significant political power (one member served as Prime Minister, 1756-1757), a power they no longer wield, yet their estates remain vast.