What big event happened in 1666?

In 1666, the Great Fire of London occurred, devastating a significant portion of the city. The fire started on September 2 and raged for four days, destroying thousands of homes, St. Paul's Cathedral, and other historic buildings. It is estimated that around 70,000 of London's 80,000 residents were left homeless. The event led to major changes in building regulations and urban planning in London.