sentences:  The longest current reigning constitutional male monarch is Carl XVI Gustaf, who is the King of Sweden.The longest reigning female monarch ever is Elizabeth II, who is currently the Queen of the United Kingdom and other Commonwealth realms, and is a constitutional monarch.She has been Queen of the United Kingdom, Australia, Canada, and New Zealand, since 6 February 1952, but all of the other countries she is at present queen were not independent at the time of her accession.