A new era opens in Spain

So many jokes about the reign in Spain concluding prematurely.  Yet if we not laughing explicitly at King Juan Carlos I, neither are we laughing implicitly with him.  This is a humiliating end for arguably one the greatest monarchical Iberian tenures since his Bourbon Enlightenment-era predecessor Carlos III (r. 1759-1788), the last king of Spain when the country was a first-rate world power.  Even going back as far as the Habsburg Phillip II (r. 1556 - 1598) when Spain was at its zenith is arguable.
Born in Rome when the Spanish Civil War was still raging and Fascist Italy was backing the Nationalists, like all those Gothic and Bulgar child hostages detained in Constantinople  to secure the adherence of these groups to the Eastern Roman cause, he was designated Francisco Franco's heir-apparent in 1969, ahead of Juan Carlos's father who had a superior claim to the throne, probably because Franco thought the child was more moulded in his image than the father.  The spectacular assassination of the ultra-hardline Luis Carrerro Blanco removed the one threat to Juan Carlos.
On Franco's death in 1975, Juan Carlos and his first prime minister Adolfo Suarez relaxed the authoritarian controls to pave the way for democratic elections in 1977.  Juan Carlos again played a key role in stopping an attempted coup in 1981, appearing in full military regalia on national television to denounce the plotters (a far cry from the Thai king who has endorsed the recent coup in his own country).  Thereafter, despite his discreet womanising, Juan Carlos seemed to play the role of constitutional monarch to perfection, not least because he operated it on the lowest budget of all the royal households in Europe (roughly 13 pence in British sterling per Spanish person).
In some ways, though he lived too long, a common failing among successful monarchs like Justinian and Heraclius in Byzantium and Edward III of England.  The press became less respectful of his extra-marital affairs and he blundered being caught on a lavish safari trip with a woman not his wife, supposedly hunting elephants, while millions of Spanish were struggling with unemployment and public services cuts.  Meanwhile his son-in-law (husband to his youngest daughter) became embroiled in financial scandal.  The falling support for the monarchy meant that Juan Carlos may have feared that what should have been a jubilant occasion, the Ruby anniversary of his reign, would be a washout.  Hence his retiral with 39 years on the throne, though the Spanish constitution will need to be amended to accommodate abdication.
Juan Carlos may have acted heedlessly.  In 2002, Queen Elizabeth's Golden Jubilee threatened to be a washout, with widespread apathy and talk of street parties scoffed at by self-proclaimed sophisticates.  Then again, Lizzie was aided first by the death of her sister Margaret and her own mother, Queen Elizabeth (her mother's final duty to the dynasty).  This unleashed massive sympathy and a restatement of royal sentiment that finally allowed the Windsors to overcome the bad blood that had existed since the death of Princess Diana.  The British monarchy has been on a uptick ever since (barring Andrew's ill-advised friendships).  The street parties took place in 2002 and in 2012.  Juan Carlos did not have the fortune of a nationally beloved aged relative to expire in a timely fashion.