It is rare that a monarch is not born in the country he will one day rule. But, when Juan Carlos was born in Rome on January 5, 1938, the chances of him acceding to the Spanish throne looked remote.
Juan Carlos' grandfather, Alfonso XIII, had been forced into exile in 1931 following two decades of turbulence for the Spanish monarchy. The former King passed away in 1941, and five years later the entire family moved to the Portuguese capital of Lisbon.
In accordance with his father's wishes that he receive part of his education in Spain, the nine-year-old Juan Carlos, still in short trousers, arrived in Madrid for the first time in 1947.
After finishing secondary school in 1954, the young Prince entered Spain's premier military academies, graduating as a naval, army and air force officer complete with pilot's wings.
He completed his education at the Complutense University of Madrid, where he studied Political and International Law, Economics and Public Spending.
In 1962, the dashing Spanish royal married Princess Sofia of Greece in Athens. Three children followed, Elena in 1963, Cristina two years later and a son and heir, Felipe
, in 1968.
Determined to ensure the country's stability after his death, the dictator Franco, then head of state, designated an apparently pliant Juan Carlos his successor in 1969. The young prince was carefully groomed for his new role and started public life in earnest, making official trips at home and abroad.
On November 22, 1975, two days after Franco's death, the 37-year-old prince was proclaimed king
. In his first speech as head of state in the Cortes, or Spanish parliament, Juan Carlos laid out the basic goals for his reign to re-establish democracy and be "King of all Spaniards, without exception".
Six years later, on the night of February 23, 1981, the new king faced a major challenge when a group of pro-Franco military officers led by Colonel Tejero launched an attempted coup. Bursting into parliament as it was in full session, they held the government to political ransom.
Within hours Juan Carlos had defused the situation, however, by appearing on television and ordering all military units to return to their garrisons. The king's decisive action meant any residual doubts about the return of the monarchy were effectively quashed.
and Sofia are proud grandparents of seven. Felipe and Letizia have a daughter Leonor (born October 2005) while Elena has two children Felipe Juan Froilán (born in July 1998) and Victoria Federica (born September 2000) and Cristina three sons, Juan Valentín (born September 1999), Pablo Nicolás (born December 2000) and Miguel (born April 2002) and a daughter Irene (born June 2005).
For a number of years there has been speculation that Juan Carlos
will step down in favour of his son Felipe
This intensified when the royal family suffered a series of setbacks.The marriage of the King's eldest daughter Elena to husband Jaime Marichalar broke down in 2009.
Then in 2012, Cristina's husband Iñaki Urdangarin became embroiled in a corruption scandal. He is currently at the centre of a judicial investigation into the Noos Institute, a foundation he headed. It is claimed the organisation was used to divert public funds.
That same year, the monarch had to apologise after he was criticised for taking an elephant hunting trip to Botswana at a time when the country was mired in financial crisis.
Once an action man, who enjoyed sailing and skiing, the King has also suffered from poor health, culminating in a series of operations on his hip.
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