In late 2014, with the war in Syria approaching its fourth year and Islamic State making gains in the north of the country, the exodus of Syrians intensified. At the same time, others were fleeing violence and poverty in countries such as Iraq, Afghanistan, Eritrea, Somalia, Niger and Kosovo.

Vast numbers of Syrian refugees had been gathering in border-town camps in neighboring Turkey, Lebanon and Jordan since 2011. By 2015, with the camps full to bursting and residents often unable to find work or educate their children, more and more people decided to seek asylum further afield.

In 2015 an estimated 1.5 million people made their way on foot from Greece towards western Europe via the "Balkan route". The Schengen Agreement, which allows passport-free travel within much of the EU, was called into question as refugees headed towards the wealthier European nations.

Tens of thousands of refugees were also attempting the perilous journey across the Mediterranean on overcrowded boats. In April 2015, 800 people of various nationalities drowned when a boat traveling from Libya capsized off the Italian coast. This was to be just one of many similar tragedies - by the end of the year, nearly 4,000 refugees were reported to have died attempting the crossing.

Countries along the EU's external border struggled to cope with the sheer number of arrivals. Fences were erected in Hungary, Slovenia, Macedonia and Austria. Asylum laws were tightened and several Schengen area countries introduced temporary border controls.

Critics of German Chancellor Angela Merkel's "open-door" refugee policy claimed it had made the situation worse by encouraging more people to embark on the dangerous journey to Europe. By September 2016, Germany had also introduced temporary checks on its border with Austria.

In early 2016, the EU and Turkey signed an agreement under which refugees arriving in Greece could be sent back to Turkey. The deal has been criticized by human rights groups and came under new strain following a vote by the European Parliament in November to freeze talks on Turkey's potential accession to the EU.

With anti-immigration sentiment in Europe growing, governments are still struggling to reach a consensus on how to handle the continuing refugee crisis. Attempts to introduce quotas for the distribution of refugees among EU member states have largely failed. Conflicts in the Middle East and elsewhere show no signs coming to an end, and the death toll from refugee sea crossings is on the rise.

Putin joined the KGB, the former Soviet Union's security agency, in 1975. In the 1980s he undertook his first foreign posting as a KGB agent to Dresden, Germany. After the fall of the Berlin Wall, Putin returned to Russia and entered Boris Yeltsin's Kremlin. When Yeltsin announced that he wanted Putin as his successor, the way was paved for him to become prime minister.

On his appointment, Putin was virtually unknown to the general public. This changed when in August 1999 armed men from Chechnya invaded the neighboring Russian territory of Dagestan. President Yeltsin appointed ex-KGB officer Putin to bring Chechnya back under the central government's control. On New Year's Eve, Yeltsin unexpectedly resigned and named Putin as acting president.

During an exhibition hockey game in Sochi, Putin’s team won 18-6, with the president scoring eight goals.

A protester wears a tape over his mouth reading "Putin" during an opposition rally. In 2013 the Kremlin announced that the state-owned news agency, RIA Novosti, was to be restructured and placed under the control of a pro-Kremlin figure known for his extreme anti-Western views. Reporters without Borders ranked Russia as 148 in its list of 178 countries in terms of press freedom.

Putin's image as a man of action, boosted by his having been a KGB spy, has long been part of his appeal in Russia. It is carefully maintained by means of photos where he is seen bare-chested on horseback, or tossing opponents onto a judo mat. In Russia, Putin has earned praise for restoring stability but has also been accused of authoritarianism.

When President Putin's United Russia party won a landslide victory in parliamentary elections in 2007, critics described the vote as neither free nor democratic. Dozens were detained as riot police broke up protests by demonstrators accusing President Putin of stifling democracy. In this rally the poster reads: "Thank you, no!"

In Sevastopol, Crimea, Putin looks through the window of a research bathyscaphe in the waters of the Black Sea. This dive in a mini-submarine was only one of his adventurous stunts; he has also been seen tranquilizing wild tigers and flying with endangered cranes. It was also aimed at cementing his image as an adventurer, and demonstrating his control of the annexed territory of Crimea.