Migrants and asylum seekers have been crossing the Mediterranean for decades. The numbers have fluctuated over the years due to a variety of factors, including conditions in countries of origin and transit, geopolitical developments, and EU policies. In 2014, at least 219,000 people made the crossing, up from 60,000 the previous year. According to the UN refugee agency United Nations High Commissioner for Refugees (UNHCR), 92,800 crossed in the first five months of 2015. The principal route has long been from North Africa across the central Mediterranean, but increasing numbers are now crossing the Aegean Sea (eastern Mediterranean) from Turkey to the Greek islands. Unprecedented numbers of people are taking dangerous journeys across the Mediterranean to reach countries of the European Union.