Ammon News - On this day in 1377, lawmakers in Ragusa—the Adriatic merchant republic we now call Dubrovnik— instituted the first quarantine in the world so as to manage the spread of the Black Death. Anyone arriving from a plague-stricken place, whether on foot or by sea, would be made to wait 30 days (later extended to 40) in isolation before entering the city. The quarantine was a success—Ragusa passed a full 44 years without any instances of the plague and shook off outbreaks that decimated the population of other regions.