Burghley House in Lincolnshire — the home of Miranda and Orlando Rock — is one of the very greatest houses in Britain. This year marks the 500th anniversary of the birth of William Cecil, a statesman of defining importance in the nation’s history. John Goodall considers the Tudor development of the great baronial seat he created for himself, while Jeremy Musson looks at the 20th and 21st century story of the house. All photographs by Paul Highnam for the Country Life Picture Library.