As a weather phenomena tornedos are not particularly associated with the UK. However a recent report by the the Met office that said that actually the UK gets more per square km than the USA. Yet our tornedos are babies for the most part and of very little power. Occasionally though we do get a whopper!
Such a huge tornedo occurred on October 17th 1091 during the reign of King William II (called Rufus). This was the first recorded tornado in the British isles and it hit London hard. It is estimated to have been about T8 strength.
The London Tornado of 1091 is reckoned to have only killed two people but dramatically the then wooden London Bridge was completely demolished (this bridge had been built by William I after the Norman conquest. After the Tornedo William II rebuilt the bridge but this too was short lived as a fire destroyed it only 40 years later).
The nearby church of St. Mary-le-Bow was badly damaged. There are reports that such was the elemental power unleashed that four rafters recorded as 26 feet long were driven so deeply into the ground that only 4 feet protruded. Around 600 houses were also destroyed.
William had recently been raiding church treasuries for funds and so there is speculation that the English would have seen this storm as a judgement by God on the wickedness of the king in the same way that some people saw the Great Fire of London as also allowed "by permission of heaven".