Possible Clues:

• Day at start of cunning year's rule in UK
• British people, but not Americans, have it, as a rule
• As a rule, it's what we're used to
• King or Queen's rule
• Wealth's chief for English system of government
• It may be limited
• Butterfly with its tail at the end, as a rule
• Wealth denied English with introduction of cunning kind of government
• King's rule
• Unusual harmony about the start of Christmas in the kingdom