The plague appears to have started in the parish of St-Giles-in-the-Fields outside of London's walls in 1664. The hot summer seems to have caused it to become an epidemic. While 68,596 deaths were recorded in the city, the true number was probably over 100,000, and other parts of the country also suffered. It was raging in the city by July 1665, and reached a peak of 7,000 deaths a week by August, but then died out during the cold winter.
Observers noticed two strains of the plague:
The plague of 1665 is significant for those who fled as much as those who stayed for the battle. Most doctors, lawyers and merchants, fled the city as did Charles II and his courtiers who left in July for Hampton Court and then Oxford. Parliament was postponed and had to sit in October at Oxford. Court cases were also moved from Westminster to Oxford.