An unprecedented 670,000 people, mainly fleeing conflict in Syria, Iraq and Afghanistan, have flooded into Europe so far this year in the continent’s worst crisis of its kind since World War II. The majority cross from Turkey into Greece and then on through the Balkans with the aim mostly of getting to Germany. Faced with a huge influx over the summer, Hungary clamped down on its border with Serbia, prompting the refugees to switch into Croatia which in turn imposed border controls, pushing them into Slovenia.