The Great Plague ended as a result of a combination of the Great Fire of London in 1666 and the colder autumn weather of that same year. While the fire helped kill off some of the plague vectors, ultimately it was the colder temperatures which ended the Great Plague.
The Great Plague was a severe outbreak of the bubonic plague which occurred in London, England, from 1665 to 1666. The bubonic plague, also known as the "Black Death," had been present in Europe for centuries, and is thought to have originated from East Asia, possibly China.
The bubonic plague caused swollen glands and black patches on the body, as well as vomiting and migraines. The plague was so severe that once a member of a household became infected, the entire family was considered doomed to die and a red cross was painted on the infected house. The bodies of those who were killed by the disease were transported out of the city and buried in mass graves.
While it is a common misconception that the Great Fire was the sole cause of the end of the Great Plague, cases of the disease were already on the decline during the time of the fire, and new cases still appeared afterward.