Bills of mortality were the weekly mortality statistics in London, produced to monitor burials especially in times of plague. The time period noted from the Black Death (1346-1353) to the last outbreak in the United Kingdom, the Great Plague (1665-1666), is known as the second pandemic in which there were intermittent reoccurring outbreaks of bubonic plague caused by the Yersinia pestis bacterium.  Beginning with regularity in 1603, the bills recorded 33,347 deaths from plague in that year. Between then and 1665, only four years had no recorded cases. The Great Plague killed an estimated 100,000 people, or almost 25% of London's population. During the winter of 1664, a bright comet was seen in the sky and the people of London were fearful, wondering what evil event it portended, it was also noted that the worst year of the plague coincided with the revelatory biblical year of 1666. This is an historic reproduction of an actual bill of mortality for the year 1666.