Complex sentence: The Cook Islands are a constitutional monarchy within the Realm of New Zealand, with Queen Elizabeth II, Queen of New Zealand, as the reigning monarch since August 4,1965.
Split into simpler sentences: The Cook Islands are a constitutional monarchy within the Realm of New Zealand. Under the Cook Islands Constitution, the Queen in right of New Zealand, is Head of State of the Cook Islands; currently Queen Elizabeth II, since August 4,1965.