Libya is the prime source of embarkation for people wanting to leave Africa for a life in Europe. This excellent, short article describes the history and the process. http://www.msnbc.com/specials/migrant-crisis/libya

In essence, until the Gadaffi regime fell in 2011, Europe was paying Gadaffi to keep Libya’s 1,100 mile (1,770 km) coastline closed. Since then there is no effective control in Libya, and therefore the coast is open. Libya is geographically near to Italy, Malta and Greece.

According to the UN Refugee Agency (UNHCR), Libya had always been a target for migrants because of the country’s prosperity and the job opportunities there. Now the job opportunities are for people smugglers who charge up to $5,000 to get people into Europe via Libya. http://www.unhcr.org/en-us/news/latest/2017/7/595a470d4.html

Furthermore, the number of people seeking a route to Europe via Libya has increased since the 2016 agreement between the EU and Turkey. This agreement was aimed at slowing the illegal entry of Syrian refugees into Greece from Turkey. The consequence has been that because the Turkey/Greece route has been blocked a ready-made alternative starting point has been found – Libya.

See http://www.bbc.com/news/world-europe-35854413 for a description of the EU-Turkey agreement.