Parishes - the old ecclesiastical administrative divisions - are now much less significant than they once were. Local authority boundaries often follow parish boundaries but sometimes ignore them, which means only part of a parish may fall within a particular borough.
Local historians tend to use these old divisions for 2 reasons. Firstly, many of the documents they use as evidence arise from the parish-based system of local government, and secondly, the parish boundaries are generally a convenient way of dividing an area for field work and recording purposes.
The old parishes of Thurrock were:
- Chadwell St Mary, incorporating Tilbury Town
- East Horndon
- East Tilbury
- Grays Thurrock
- Langdon Hills
- Little Thurrock
- Little Warley
- South Ockendon
- West Horndon
- West Thurrock, incorporating Purfleet
- West Tilbury