The Dublin Regulation is a European Union (EU) law that determines as quickly as possible the EU Member State responsible for examining an asylum application. The principle is that only one Member state is responsible for the application for international protection, which prevents the submission of multiple applications by one person and avoids refugees from being sent from one country to another. The country to which refugees first apply for asylum has to either accept or reject asylum, and refugees cannot restart the process in another country. Usually, the responsible Member State is the state through which the asylum seeker first enters the EU. When an asylum seeker has illegally crossed the border into a Member State, the Member State has the responsibility to examine the asylum application. This responsibility ceases 12 months after the date on which the border has been illegally crossed. If an asylum seeker has a family member who is legally living in a Member State, the Member State is responsible for examining the application. When the asylum seeker possesses a valid visa or residence document, the Member State that issued it is responsible for examining the application. If one has more than one valid visa or residence document, the Member State that granted the longest period of residency has to be responsible for the asylum claim. The protection of refugees has been an international responsibility since the early 1950s with the introduction of the Geneva Convention. According to Refugee Convention in 1951, any person who is under "fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion" has a right to be granted international protection. It was not until the 1980s and 1990s that refugee issues were addressed within the EU. In 1990, the Dublin Convention was established; in 2003 it grew into the Dublin II Regulation and then developed into the Dublin III Regulation in 2013. In April 2015, five boats carrying about 2,000 migrants to Europe sank in the Mediterranean Sea, which claimed 1,200 lives. This tragedy resulted in the wide use of the term "European migrant crisis." Under the Dublin Regulation, if one who has filed for asylum in an EU country illegally crosses borders to another country, they shall be returned to the former. In June 2015, Hungary was so overburdened by asylum applications that it refused to receive back the applicants who later crossed to another EU country. In August 2015, Germany, having been complaining the Dublin Regulation is failing, quietly stopped to enforce the regulation and processed applications from Syrians even if they have made their way through other EU countries.