Oldest quarantine

The earliest legally enforced quarantine was established in 549 CE by Justinian, the Eastern Roman Emperor. During the pandemic known as the Plague of Justinian (which lasted from 541 to 750 CE), he passed a series of laws designed to bar plague-carrying "outsiders" of various kinds (mostly already-marginalized minorities) from the capital, Byzantium, and its environs.

The basic principle behind quarantines has been around for most of human history. The Old Testament of the Bible (Leviticus 13) suggests isolating sick individuals from healthy populations, particularly in reference to plague and leprosy.

The Plague of Justinian lasted from around 541 to 750 CE, killing up to half of the population of the Mediterranean and contributed towards the fall of the Roman Empire. In Europe, the practice of quarantine expanded during the Black Death pandemic of the fourteenth century. The word quarantine originates from fourteenth century Italy. In an attempt to protect the city from plague, ships arriving in Venice from areas with plague were required to wait offshore for 40 days before they were allowed to land. The word ‘quarantine’ comes from the Italian words quaranta giorni, meaning 40 days.