Complex sentence: The new royal couple lived a secluded life and although pietist surrounded by luxuriant splendor, hidden in enclosed carriages with its curtains down, behind one of Denmark's history most tyrannical, repressive, and puritanical eras.
Split into simpler sentences: The new royal couple lived a secluded life and, although pietist, were surrounded by luxuriant splendor. Behind the curtains of their enclosed carriages lay one of Denmark's most tyrannical, repressive, and puritanical eras.