Bubonic plague The bubonic plague — commonly called the Black Death and clinically Yersinia pestis ( COMIC : " Black Death White Life " ) — was a devastating disease which originated in the Middle Ages . It was spread by rat s and flea s due to the poor sanitation of that age . ( TV : " The Visitation " ) History . 13th century . The entity known as the Pied Piper fed on the fear of the plague in Hamelin in 1283 and 1284 . ( TV : " The Day of the Clown " ) 14th century . According to the First Doctor , a large epidemic of bubonic plague originated in 1346 when Mongol s in Janibeg Khan ' s army besieged Kaffa . The commander of Kaffa ' s defenders ordered diseased corpses to be catapulted beyond the city walls . The illness could spread to the Mongols , killing many of them . Dodo Chaplet feared the idea was possibly influenced by a similar strategy employed against the Mongols at Kiev in the 13th century , and it came to be regarded as the first instance of biological warfare . Soon , Genoese merchant s travelled across the Mediterranean , spreading the plague to ports in southern Europe . It moved on to Spain , France , Germany and Britain , and then to Scandinavia and Greenland . One third of the European population died as a result of the plague . ( PROSE : " Bunker Soldiers " ) Ashildr fell victim to the Black Death in 1348 . Her immune system coped and she got better , in no small part due to having been rendered effectively immortal since the 9th century due to an implanted Mire repair kit , but her children Essie , Johann , and Rue died . ( PROSE : " The Triple Knife " , TV : " The Woman Who Lived " ) 15th century . In 1479 , Duroc , also known as Death , appeared during a bubonic plague outbreak in Cardiff until Faith stopped it before it could claim its thirteenth victim and enter the universe permanently . ( TV : " Dead Man Walking " ) 16th century . When a colony of Saturnyn came to Venice in 1580 , they claimed that there was an outbreak of plague , allowing them to isolate Venice . ( TV : " The Vampires of Venice " ) William Shakespeare ' s son was a victim . It was grief over his death that brought Shakespeare to his lowest emotional ebb , allowing the Carrionite s to manipulate him . ( TV : " The Shakespeare Code " ) 17th century . Barnaby ' s parents died from the bubonic plague prior to 1605 . ( GAME : " The Gunpowder Plot " ) In 1666 , escaped Terileptil convicts created a deliberately more virulent variant on the Black Death in order to infect rat s with it so as to spread it to human s . The Fifth Doctor defeated them , eliminating the storage of viruses in the Great Fire of London , which was unintentionally set whilst fighting the Terileptils . ( TV : " The Visitation " ) Another outbreak appeared to have occurred in a village in 1669 . In fact , it was an instance of Macro - virus es . ( COMIC : " Black Death White Life " ) 19th century . Memories of the plague persisted as far as the 19th century and any unexplained death was attributed to the plague or , in more bizarre cases , the legendary Plague Warriors . ( PROSE : " Plague of the Cybermen " ) 20th century . In 1933 , in the Zhong Ma Fortress in occupied Manchuria , the Japan ese military scientist Ishii Shiro led experimentation into biological weapons development . They infected their Chinese prisoner s with bubonic plague to study its effects on the human body in order to weaponise the germs . In one case , the plague spread to the victim ' s lung s and evolved into the highly contagious and , without treatment , 100 % fatal pneumonic plague . The research was used to kill hundreds of thousands during World War II before Japan surrendered to the United States in 1945 . To prevent the Russia ns finding out about the research , and for their own medical purposes , the Americans did not persecute the Japanese perpetrators , and even used it themselves in the Korean War . ( PROSE : " Log 384 " ) 21st century . When the Cardiff Space - Time Rift became more active after it was opened by the Rift Manipulator , at least one female victim of the Bubonic plague came through into a hospital in 2008 . She died shortly after , in isolation , but not before her presence at the hospital caused an outbreak of the plague . ( TV : " End of Days " ) The Hotel Historia had rooms contaminated with the Black Death . The Tenth Doctor was displeased with them . ( COMIC : " Hotel Historia " ) Behind the scenes . One possible " game over " for the video game " Don ' t Blink " has the player being sent back in time by a Weeping Angel to the year 1348 to die of Black Death .