Colchester Archaeological Trust

CAT Report 2135: summary

Archaeological investigation of Mersea Blockhouse, 300m south of Mersea Stone, East Mersea, Essex: October 2024
by Laura Pooley and Alec Wade (with contributions from Dr Matthew Loughton, Alec Wade, Tabitha Lawrence and Alan Chapman)

Date report completed: March 2025
Location: Mersea Blockhouse, 300m south of Mersea Stone, East Mersea, Essex
Map reference(s): TM 07195 15166
File size: 13,455 kb
Project type: Archaeological investigation
Significance of the results:
Keywords:

Summary. An archaeological investigation took place at Mersea Blockhouse, 300m south of Mersea Stone, East Mersea, Essex. The blockhouse (fort) is a Scheduled Ancient Monument (NHLE 1013832) situated in low-lying marshland the sea wall at the mouth of the Colne Estuary. First built in 1543 as part of Henry VIII’s extensive programme of coastal military defence, it was used and adapted periodically in times of unrest until the 19th century. A map of 1656 shows it was a triangular earthwork with semi-circular bastions in each corner. The archaeological investigation was commissioned by Essex County Council in response to damage being caused to part of the monument by coastal erosion. The investigation focussed on a small earthwork mound closest to the sea, thought to be part of a southern rampart. The seaward face of that mound was cut back to form a flat section through the surviving earthwork. The section was hand-drawn, with photogrammetry carried out before and after the section was cut. The mound represented a small part of both the southern rampart and the easternmost (seaward) bastion. To the south of the rampart part of a possible outer moat was also identified. Layers recorded appear to be associated with the Henrican blockhouse and phases of refurbishment and repairs in the 17th century.