Possible Clues:

• Henry VIII, for one
• English ruling house after York
• Royal family name of two of Trollope's civil servants (the third was Norman)
• House of two Henrys
• British-inspired home style
• Old house's study needing work after demolition of wings
• Henry VII and Henry VIII, for two
• Elizabeth I of England was of this royal family
• Staff extremely upset about royal house
• Royal house died in defeat, overthrown