Top-down change in differing degrees has been decreed by rulers in Morocco, Jordan, Oman, Saudi Arabia, the United Arab Emirates, Qatar and Kuwait. On balance, many of these monarchies have helped those countries move forward, if far too slowly, with social, economic and political reform. But even these monarchies risk being overtaken by the global revolutions of cross-border trade, social media and instant communications. Their common challenge is now to adapt more rapidly or die.

European monarchies have adeptly moved with the times. They have become useful as symbols of national unity in divided countries, or dignified national arbiters of political conflicts. They can also become tourist attractions or, in the case of the United Kingdom, all of the above. No sentient being who has met Queen Elizabeth could come away wishing she simply did not exist.

The decision by Juan Carlos to quit playing the game of thrones gives Spain the obligation and opportunity to debate the validity of monarchy in modern Europe.