A statuesque 6ft chain-smoker, with a penchant for brightly coloured raincoats and a remarkable sideline in the arts, she is one of the most admired — and flamboyant — of European monarchs. But two days ago, during her New Year’s Eve address, Queen Margrethe II of Denmark shocked her nation and royal watchers worldwide by announcing her decision to abdicate. From January 14, her son Crown Prince Frederik will be King — and her 52-year reign will be over. Yesterday, rumours swirled among her six million subjects over what could have prompted such a move from the 83-year-old who once...