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.

For more than 40 years, Moammar Gadhafi was the eccentric strongman in power in Libya. He was known for his odd behavior - and for his regime's ties to international terror groups. Libya was one of the countries swept up by the Arab Spring, and protests eventually turned into a civil war. Gadhafi fled but was eventually captured and killed In October, 2011.

After Gadhafi fell, the eyes of the world were on Libya in the hope that the country would have a smooth transition to democracy. By July 2012, democratic parliamentary elections had taken place, but it proved to be a challenge for the country's politicians to form a coalition and compromise on issues that would bring further stability.

Another problem facing Libya in the post-Gadhafi era was the rise of violent militias. While various armed groups did band together to topple the dictator, they did not have a common cause to rally around after his death. Instead, they fought each other. Terrorist groups were also on the rise in Libya, and staged a deadly attack on the US embassy in Benghazi on September 11, 2012.

Political divisions became deeper in the years following Gadhafi's ouster. The UN-backed Government of National Accord (GNA) is the internationally-recognized authority in Libya, but several factions on the ground are claiming a hold on power. Jihadist groups including the so-called 'Islamic State' have gained a significant foothold in the country, making any progress precarious.

At present, the Tripoli-based GNA controls parts of western and central Libya while Haftar's Libyan National Army holds much of the northeast. However, areas of power are constantly shifting due to ongoing "Islamic State" violence and the country's many different smaller factions.

In recent weeks, Libya has reached out to NATO for assistance in strengthening the country's security institutions in an effort to end the power struggle between competing governments and militias. Leaders of two of the biggest groups - the GNA and the self-proclaimed Libyan National Army LNA - called for an end to the political and economic crises in the country.