King Juan Carlos of Spain has abdicated, Prime Minister Mariano Rajoy has announced.
Photographs of the king signing the official papers, together with a letter announcing his decison, were released by the royal family on Twitter.
The surprise announcement comes after a dramatic decline in the popularity of King Juan Carlos, 76, who has ruled since 1975.

First, the King was discovered to have traveled to Africa on a big-game hunting expedition, shooting elephant in private game reserves, and the past year has seen wave after wave of negative publicity as his daughter, the Infanta Cristina, and her husband have been the focus of a long-running corruption investigation.
Juan Carlos's son Prince Felipe, 45, will take over the throne.
Juan Carlos’s resignation as King marks an extraordinary gamble on the part of the Spanish monarchy.
Despite the recent scandals, the Spanish retain a huge affection for their King as it was he who bloodlessly delivered the country from the nightmare of the Franco dictatorship, which ruled Spain from 1939 to 1975.
Toward the end of his life, Franco handed over power to Juan Carlos, the hereditary king, which he thought would be a way of maintaining an absolute, non-democratic state.
However, Juan Carlos effectively tricked him. During his lifetime he espoused pro-Franco views, but was secretly meeting with the liberal opposition and political dissenters, and two days after Franco’s death he announced far reaching democratic reforms.
“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,” Prime Minister Mariano Rajoy said this morning.
Juan Carlos is the second European monarch to abdicate in just over a year. In April last year, Queen Beatrix of the Netherlands handed the throne to her son Prince Willem-Alexander after 33 years.
We assume Prince Charles is currently glued to the news feed.
The abdication has caught most observers by surprise, but it was predicted by Lars Hovbakke Sørensen, a lecturer in European royalty at the University of Copenhagen, when he spoke to the Daily Beast’s Nico Hines earlier this year.
“Cristina is seen as being close to the king; her problems are the king’s problems,” he told The Daily Beast. “I wouldn’t be surprised if King Juan Carlos chooses to resign in the coming months, and hands over the throne to Crown Prince Felipe in an attempt to save the monarchy.”