The London Tornado of 1091 is reckoned by modern assessment of the reports as possibly a T8 tornado (roughly equal to an F4 tornado) which occurred in London, England. Britain's earliest reported tornado, it occurred on Friday, 17 October 1091, killing two.[note 1] The wooden London Bridge was demolished, and the church of St. Mary-le-Bow in the city of London was badly damaged; four rafters 26 feet (7.9 m) long were driven into the ground with such force that only 4 feet (1.2 m) protruded above the surface. Other churches in the area were demolished, as were over 600 (mostly wooden) houses.
At the turn of the millennium, London was a city far smaller than it is now. In the year 140AD there were about 45-60,000 inhabitants of Londinium. The city size rapidly depopulated with the fall of the Empire and by 300CAD there were only 10-20,000 residents. By the beginning of the second millennium, the population had dwindled to only 5-10,000 but it was picking back up. With the destruction of the Cnut dynasty in 1042, English rule came under Edward the Confessor and the foundation of Westminster Abbey is credited to him. By the end of the century there were probably about 18,000 inhabitants to bear witness to the gigantic twister as it tore apart their city. It is remarkable to note that for all the damage inflicted, the tornado claimed just two victims.