Following the Great Fire of London (1666), the city of London was completely rebuilt. New planning laws, governing rebuilding, designated four types of street based on the size of their carriageways and the types of buildings. Shops were permitted in the principal street or 'high street', but not in the by-lanes or back streets. This may have been based on the need for high visibility in order to regulate retail trade, as well as to avoid congestion in the narrow lanes and back streets. Accordingly, from the 17th century, the term "High Street" gradually assumed a narrower meaning and came to describe thoroughfares with significant retail in large villages and towns.