The county of Middlesex was divided into hundreds. Some of the hundreds were further divided into divisions. Within each division were a number of parishes. Parishes, such as Heston, are called 'ancient parishes' and have probably been in existence since 1500. These so called ancient parishes are listed here in alphabetical order. New parishes were created out of existing parishes (often more than one). As an example Twickenham Common was created out of Twickenham in 1842. Hounslow was created partly from Heston and partly from Isleworth in 1836. Parishes created after 1929 are not listed.