Spain's King Juan Carlos is abdicating to allow his son Prince Felipe to take over, the country's Prime Minister has announced.
Mariano Rajoy addressed the nation to say that there would be an amendment to the constitution to allow the 46-year-old Crown Prince to take over.
The 76-year-old king oversaw his country's transition from dictatorship to democracy but in recent years has had repeated health problems.
In the last few years the monarchy has been beset by scandals, which included a furore over an elephant hunting trip Juan Carlos took during the financial crisis.
In the last few months, his daughter the Infanta Cristina has appeared in court to face questions over an financial allegations which have engulfed her husband.
Crown Prince Felipe will take over from his father
The king came to power in 1975, two days after the death of the dictator Francisco Franco, who won a bloody civil war in the late 1930s.
Mr Rajoy said: "His majesty, King Juan Carlos, has just communicated to me his will to give up the throne. I'm convinced this is the best moment for change."
His move comes a year after a similar one by the Dutch former Queen Beatrix, who stood aside to allow her son Crown Prince Willem-Alexander to take the throne.
That abdication prompted speculation that the British Queen Elizabeth II may do something similar.
Pablo Foley Elias is a journalist in Madrid and he says the Spanish people are in shock, though the decision was taken some time ago:
