Complex sentence: The Marquess, so against enforced preservation was, in fact, a member of the Royal Commission of Ancient and Historical Monuments, in the House of Lords, the very body who oversaw the implementation of the acts intended to enforce preservation.
Split into simpler sentences: The Marquess, so against enforced preservation was, in fact, a member of the Royal Commission of Ancient and Historical Monuments, in the House of Lords. The very body who oversaw the implementation of the acts intended to enforce preservation.