In what the UN has described as "the biggest humanitarian emergency of our era", by 2014 about 9.5 million Syrians, half the population, had been displaced since the outbreak of the Syrian Civil War in March 2011; 4 million were outside the country as refugees. By 2020, the UN estimated that over 5.5 million Syrians were living as refugees in the region, and 6.1 million others were internally displaced.