More than a million people fleeing war, persecution and poverty in the Middle East and Africa crossed the Mediterranean to Europe in 2015. The number of people who died making the perilous crossing in often unseaworthy boats and dinghies was at least 3,770. So far this year, more than 76,000 people have reached Europe by sea — nearly 2,000 per day — and 409 of them have died trying, most drowning in the cold, rough waters. The number of arrivals in the first six weeks of 2016 is nearly 10 times as many as the same period last year.

The influx of refugees has plunged the European Union into what some see as the most serious crisis in its history. In response, Nato has ordered three warships to sail immediately to the Aegean Sea to help end the deadly smuggling of asylum-seekers across the sea from Turkey to Greece. However, there is uncertainty about the precise actions they would be performing, including whether they would take part in operations to rescue drowning people.

refugee crisis
8 February 2016: A man, identified as 20-year old Pelen Hussein from Syria, stands on top of a capsized boat as he waits to be rescued by the Turkish Coast Guard Air Command in the Aegean Sea off the waters of Edremit bay, Turkey. Twenty-seven migrants, 11 of them children, drowned off Turkey's Aegean coastTurkish Coast Guard Command/Reuters
refugee crisis
A Greek Coast Guard officer pulls a man out of the Aegean during a rescue operation between the Turkish coast and the island of LesbosGiorgos Moutafis/Reuters
refugee crisis
8 February 2016: Rescuers help a girl out of a dinghy carrying refugees and migrants and onto a Greek Coast Guard vessel in the open sea between Turkey and LesbosGiorgos Moutafis/Reuters
refugee crisis
31 January 2016: A boat that capsized off Canakkale in Turkey, killing at least 37 people, sinks slowly into the Aegean SeaOzan Kose/AFP
refugee crisis
27 January 2016: African men thank God as they arrive in Malaga after their inflatable boat was rescued by the Spanish coast guardJorge Guerrero/AFP
refugee crisis
16 January 2016: Ahmad Zarour, 32, from Syria,is rescued by MOAS (Migrant Offshore Aid Station) while attempting to reach the Greek island of AgathonisiAngelos Tzortzinis/AFP
refugee crisis
10 November 2015: A man on an inflatable boat arrives to rescue someone in the open sea near the shores of the Greek island of LesbosAlkis Konstantinidis/Reuters
refugee crisis
30 October 2015: A refugee prepares to hand over a toddler to a volunteer lifeguard as a catamaran carrying around 150 refugees, most of them Syrians, sinks off the Greek island of LesbosGiorgos Moutafis/Reuters
refugee crisis
30 October 2015: Rescue workers on a jet ski help refugees and migrants off a sinking boat near the Greek island of LesbosAris Messinis/AFP
refugee crisis
30 October 2015: Syrian Kurdish refugees are rescued by Greek fishermen as their boat sank off the Greek island of LesbosAris Messinis/AFP
refugee crisis
30 October 2015: A boy cries out for help as a catamaran carrying around 150 refugees, most of them Syrians, begins to sink off the Greek island of LesbosGiorgos Moutafis/Reuters
refugee crisis
28 October 2015: Volunteer doctors and paramedics try to revive a baby after a boat carrying more than 200 refugees and migrants sank off the Greek island of LesbosGiorgos Moutafis/Reuters
refugee crisis
15 october 2015: A Greek coast guard diver pulls the body of a refugee child away from a sunken wooden boat near the Greek island of LesbosGiorgos Moutafis/Reuters
refugee crisis
19 September 2015: A local Greek man helps an Afghan refugee struggling in the water after he jumped into the sea without a life vest from a dinghy with a broken engine off the Greek island of LesbosYannis Behrakis/Reuters
News photos of the year 2015
2 September 2015: A Turkish police officer carries the body of a Syrian refugee child named Alan Kurdi who washed up on a beach in Bodrum, Turkey, after a boat sank while reaching the Greek island of KosNilufer Demir/AFP
refugee crisis
11 August 2015: A man is rescued by an Italian Navy helicopter after a rubber dinghy sank in the Mediterranean SeaItalian Navy/Reuters
refugee crisis
6 August 2015: People hang onto flotation tubes in the sea after jumping from an overloaded wooden boat during a rescue operation off the coast of LibyaDarrin Zammit Lupi/Reuters
refugee crisis
3 August 2015: A rescue worker reaches out to a man on a rubber dinghy off the coast of LibyaDarrin Zammit Lupi/Reuters
refugee crisis
14 May 2015: Around 300 sub-Saharan African people sit onboard a boat during a rescue operation by an Italian police vessel off the coast of SicilyAlessandro Bianchi/Reuters
refugee crisis
20 April 2015: Local residents and rescue workers help a woman after a boat sank off the island of Rhodes, killing at least three people, including a childArgiris Mantikos/AFP
2015 migrants
20 April 2015: The body of a person who died after a fishing boat capsized off the Libyan coast, is brought ashore by the Italian Coast Guard vessel Bruno Gregoretti at Boiler Wharf, Senglea in Malta. More than 700 people were feared dead following the capsizing of a boat that had been crammed with people trying to reach EuropeMatthew Mirabelli/AFP

The record movement of people into Europe is a symptom of a record level of disruption around the globe, with numbers of refugees and internally displaced people far surpassing 60 million, according to the UN refugee agency. The war in Syria is only one among many causes, including Ebola and Boko Haram in west Africa, an earthquake in Nepal, conflicts in Libya, Yemen, South Sudan, Central African Republic and Afghanistan and Iraq.

Greece, with thousands of kilometres of coastline and islands very near the Turkish coast, is the main gateway into Europe for those fleeing the Middle East, while Italy, Malta and Spain are the main destinations for those making the journey from north and west Africa.