Purfleet falls within the parish of West Thurrock. In the reign of George III, Purfleet Garrison was built to service 5 powder magazines, arising from concern that powder stored at Woolwich presented a potential danger to London. It was designed by James Gabriel Montresor who also supervised the construction. One of the magazines (No.5) and the proofing house have been preserved. The magazines were built of brick with thickly copper plated doors. The nails are copper and the roof space was filled with sand. There are no windows. All the buildings were designed to protect the surrounding area should an explosion occur. The magazines could house 50,000 barrels of gunpowder.

The Purfleet Heritage and Military Centre is housed within what was once Magazine No.5. The centre contains a wide range of historical artifacts and memorabilia relating to the history of the magazines and local area dating from 18th Century to present day.

In April 2012, a plaque was unveiled at Purfleet celebrating Benjamin Franklin who visited the Royal Gunpowder Magazine in the 1760s and offered advice (that was rejected) on the most effective design for lightning conductors to reduce the risk of an explosion from lightning strikes.

See "Exploring Thurrock" by Chris Harrold and Panorama 28.