Juan Carlos I: he was the King who ensured Spain's democratic transition after Franco's military dictatorship. But a disastrous hunting trip to Botswana saw his public favour plunge in 2012 - and in 2014, he dramatically abdicated from the throne. Was money his undoing? His sexual conquests? Now forced into exile in Abu Dhabi, Juan Carlos is at the heart of a scandalous saga that some say could even endanger the Spanish monarchy.