How did the fire spread?

The summer of 1666 was hot and long, and by September most of London was tinder dry.

Almost all the houses were built with wooden frames. These are known as timber-framed houses. Some  houses had thatched roofs.

A strong east wind blew, sending the the flames of the fire from house to house across the very narrow streets.

Many buildings were warehouses which stored barrels
of brandy and spirits and oil which are very flammable. The barrels exploded in the heat and threw balls of
flame out of windows and doors.