Cudmore Grove, East Mersea

Mersea Island contains a wealth of archaeology set against a heavily eroding foreshore environment that is receding by as much as a metre per year in places. East Mersea is home to a line of pill boxes and observation posts that now lie crumbling on the foreshore, fallen from the cliff line upon which they stood in the 1940s. The area also contains a scheduled ancient monument in the form of Tudor Block House that was surveyed in the early 2000s but that is now gently being eroded away by the waves. There are numerous post alignments in the intertidal mudflats and the remains of several boat hulks to also explore.

We’ll be working with our partners at Cudmore Grove Country Park, Essex County Council as well as local volunteer groups and the Mersea Museum to survey the area. Aside from a survey of the defensive structure there will be a focus on resurveying the Block House to assess the extent of the erosion that has occurred at the site since the original Historic England survey early this century.

West Mersea is equally rich in archaeology and over the course of years two and three of the project we’ll be working with the Crown Estate and RSPB volunteers to record a variety of sites. We’ll also be working with our partner the National Trust to survey Ray Island, a large sandy mound lying between Mersea Island and the mainland.

Mersea’s Tudor Fort

The fort was part of an extensive system of coastal defences constructed on the orders of Henry VIII in c. 1543, to protect England against seaborne threats by the catholic powers of France and Spain. It was a triangular earthwork with guns mounted on the corner turrets. Each side was about 100m long topped with a palisade and surrounded by a defensive ditch. When the initial fears of invasion receded, the fort was abandoned by the military, but refortified in 1588 when the very real threat posed by the Spanish Armada loomed large.

Reconstruction of Mersea Fort in the 17th Century
Reconstruction of Mersea Fort in the 17th Century

It was subsequently maintained, and was still operative when the Civil War erupted between king and parliament in 1642. In 1648, the old Tudor fort was held by the Parliamentarians during the 75-day siege of Colchester, and played a key strategic role in that important episode with the blockade of the River Colne river. Once the Civil War was over, the fort was decommissioned and unmaintained until the late 18th and early 19th century, when the Napoleonic Wars posed another invasion threat and saw the defences refurbished for the last time. Thereafter, it was once again allowed to decay, and now is threatened, not by invading armies, but by increasingly severe coastal erosion.

1656 map showing the fort and fields in the area
1656 map showing the fort and fields in the area

A recent survey by the CITiZAN team of the fort recorded various features on the adjacent foreshore, including the remains of a post and wattle structure. This had not been visible on a previous visit, demonstrating how aggressive the erosion is in this reach. Samples from the wattlework have now been dated to between AD1461 and 1636, and thus the structure probably functioned at the same time as the fort. Initial interpretations suggest it may have been part of a fish trap, perhaps used by the garrison to augment their food supplies. Other interpretations are of course possible, but more detailed survey and research are required to help us understand this intriguing feature.

CITiZAN survey of the possible fish trap at Mersea
CITiZAN survey of the possible fish trap at Mersea