Formerly part of the Manor of Canford, the historic tything of Longfleet is mentioned in the Pipe Rolls of 1230. It became a parish in its own right in 1833 and now forms part of the modern Borough of Poole.
Tatnam Farmhouse was built in the early 19th Century
Early references to Tatnam date back to documents in 1520. It was here that Tatnam Well was built to supply water to the town of Poole.
The Church of Longfleet St. Mary was consecrated on 25th September 1833.
Originally designed by Edward Blore, the church has been largely rebuilt during the course of its history. In the latter part of the 19th Century a chancel and organ chamber were added, while in 1884, the western end was enlarged with the addition of a spire 135 feet. high. Further building work took place in 1915.