Registration of deaths in England began in the mid 16th century. I will discuss our ongoing efforts to quantify epidemic patterns both before and during the death registration era. A major challenge is to determine whether data we are able to collect truly reflect the epidemics. In addition, without assuming a particular model concerning interaction of rats, fleas and humans, we are attempting to compare growth rates of epidemics in London from the Black Death in 1348 to the Great Plague in 1665.