Many islanders are familiar with Mersea's surviving military defences - the concrete pill-boxes and crumbling gun placements built 70 years ago to guard against Nazi invasion. But these very visible features are not the only evidence of the island's role in times of war, whether against foreign powers or even fellow Englishmen. Old maps show a mysterious 'Blockhouse' close to East Mersea Stone, where a spit of land juts out into the mouth of the River Colne. If you visit the site, you can still find the earthwork remains of a triangular construction more than four centuries old. Isolated and eroded, it is barely noticeable among the tidal lagoons and saltmarsh, and the landward side of the triangle has been obliterated by construction of the sea wall. If you then visit Mersea Island Museum and look among the 17th century exhibits, you can see a collection of civil war cannon balls, found at the site of this small, outlying fort, or blockhouse.
Remains of Blockhouse Fort at East Mersea.
1656 map showing the fort and fields in the area.
Reconstruction of Mersea Fort in the 17th Century.
Drawing: Cudmore Grove Country Park / Essex County Council.
Mersea's historic fort was first constructed on the orders of King Henry VIII, one of a chain of 'Device Forts' built around the coast to protect from invasion by France or Spain. Listed with similar defences at St Osyth and Brightlingsea as 'bulwarkes of earth and board', it was a simple triangular earthwork with sides of about 100 yards in length, topped with a palisade and surrounded by a defensive ditch. It was intended that 12 cannon would be mounted on the three corner turrets. When fears of invasion receded, the fort was abandoned, its house occupied only by a 'poor old widow', while the four remaining cannon slowly filled with earth. A new, urgent threat from the Spanish Armada in 1588 led to repairs, reinforcements and the arrival of additional cannon, and the Mersea fort continued to be maintained, listed as an effective fort in the Ord nce Office books of 1631.
When civil war first erupted between king and parliament in 1642, Mersea was fortunate to avoid the attention of competing armies. Life on this quiet backwater continued largely unchanged until June, 1648, and the brutal events of the second civil war. Royalist supporters of the imprisoned King Charles I marched from Kent, gathering forces and joining with Essex Royalists led by Sir Charles Lucas. Resisting the pursuit of the Parliamentarian General Fairfax, they forced their way into the walled town of Colchester with more than 5,000 cavalry and foot soldiers. Realising that most of the 10,000 townspeople were strong supporters of Parliament, the Royalist leaders planned to rest for one night only, before continuing their march northward to unite with other Royalist forces. Unfortunately for them, and even more so for Colchester, Fairfax immediately arrived on the scene with 4,000 troops of the New Model Army. Failing to break through the fortified gates, he set about besieging the town, building elaborate fortifications from which to assault the defences on every side. His intention was to cut off supplies and rapidly starve Colchester into surrender. However, the Royalists were able to seize corn, wine, salt, fish and gunpowder stored in warehouses at the Hythe, allowing them to withstand the siege for 75 increasingly desperate days.
As a leading centre of cloth-making and trade, Colchester's main supply route was the River Colne, its approaches guarded by the fort at Mersea. Following their victory in the first civil war, Parliament ordered many fortifications, including Mersea Fort, to be 'disgarisoned'. However, the resurgence of hostilities in 1648 suddenly brought the island into the front line. Before the Royalists could send a troop to take possession of the fort and allow their ships upriver, General Fairfax had dispatched Colonel Zanchy's cavalry troop to Mersea. At the same time he arranged for six Parliamentarian ships from Harwich, led by Captain James Peacock on The Tyger, to set up a blockade. On Mersea Island, there was little resistance, and the fort with its five cannon quickly fell into Parliamentarian hands. On 15th June, 1648, the Speaker of the House of Commons received a letter, reporting, among other details of the siege, that 'Mersey Fort [was] taken, with two Culverins, two Sakers and one Drake'. Some of the ammunition stockpiled for these guns may be among the cannon balls found many centuries later on the site of the fort.
Demi-culverin cannon cast in 1587. Image with thanks to WyrdLight.com.
Cannon Balls in Mersea Museum.
There are several eye-witness accounts of the siege of Colchester. The Royalist quarter-master, Matthew Carter, kept a jour l of events inside the besieged town. He made rueful excuses for the Royalists' failure to capture Mersea Fort, widely seen as a major contribution to their defeat at Colchester, which in its turn led to the king's execution the following year. Carter explained that the fort would be too isolated for the Royalists to defend; their forces were too small to be divided and islanders might be hostile: 'In our consultation about taking Mersea Fort, and placing a guard there, we found that the said island was not capable of relieving and supporting half the body of men necessary for the defence and security of the place.' However, on 20th June the Royalists did send out a raiding party of 300 men 'to make a show of attacking' the fort, but their only success was to seize from local people 'a good number of cattle' and 'five wagons laden with corn', which were quickly driven back into Colchester. One attempt was made to run the blockade of the River Colne. On 18th June two Royalist frigates managed to deliver men and supplies to the Hythe, but they were intercepted on their return and, after a brief gunfight, captured and towed into Brightlingsea.
Mersea Island now found itself under military occupation. Captain William Burrell was appointed commander of the island and its garrison. As well as occupying the fort, troops were billeted on local people, 'the alehouses not being sufficient or fit'. After the execution of King Charles, Cromwell's government was fearful of Royalist uprisings, and sent frequent orders to Captain Burrell and the Essex Militia Commissioners to reinforce Mersea's defences. In July 1650, 'two iron guns and one brass one' were moved from Colchester to defend the fort, and the Council of State reported that '14 barrels of powder, 40 demi-culverin round shot, 40 sacker shot, 5cwt of small shot, a demi-culverin carriage, and three pairs of wheels and axle trees of 15 lbs have been issued to the Governor of Mersey Island.' In August the garrison of around 12 cavalrymen and 24 foot soldiers was temporarily increased by the arrival of 'a squadron of horse and 50 foot, under able commanders … to receive orders from Capt. Burrell, the governor there.' In the autumn of 1650, the governor's pay was increased to 8 shillings per day, while £9.10s 9d was spent on stores for the garrison. Nothing was overlooked, with £33 being spent on 'ladles' for Mersea and other garrisons, while xxAn Walford was paid £2.5s.0d to make a flag for the island 'of 12 breadths and 5 yards long', no doubt displaying the arms of the new Commonwealth government.
In addition to the need for troops, arms and ammunition, concern was expressed in 1651 that the fort was falling into disrepair and vulnerable to the enemy: 'and the safety of those parts of the country depends on your keeping that island.' Captain Burrell was ordered to call in labourers from surrounding areas along with supplies of turf, which were constantly required to protect the earthwork defences from erosion. In March 1653 the governor petitioned for £17 10s for turf already used, with a further £10 required. He also requested that £100 be spent on 'a timber house for the gunners and their assistants', which probably continued to be occupied when the fort was abandoned.
As well as guarding the coast from incursions by Royalists and their foreign allies, the Governor of Mersea Island had more local duties to perform. He was ordered to remove the Rector of East Mersea, Israel Edwards, who had been the incumbent there for 35 years. Parson Edwardes was to be sent '10 miles out of the island', and replaced by a minister of more acceptably puritan inclinations. The same fate befell John Woodhouse, Vicar of West Mersea, who had been 'ejected' for Royalist sympathies in 1642 but still lived locally. Captain Burrell approved the appointment of Arthur Okeley, who had found favour with West Mersea parishioners - 15 of them signed a petition in his favour, headed by the churchwarden, John Smith.
A renewed threat from Royalist insurgents threatened the coast of Essex in 1655, when Lord Wilmot landed in Yorkshire, but his supporters and others in the West of England were easily dispersed by the Protector's troops. 72 Royalists were arrested in the Eastern counties and sent as prisoners to various strongholds, including Mersea, which received Henry Lernon of Stanway Hall, with William Barradell and Captain Barker of Colchester. However, with the total failure of the Royalist uprising, they were soon released on bond. Finally it appeared that the Commonwealth government of Oliver Cromwell was secure, and attention was now devoted to paying off the armies and reducing the country's defence costs. A list was drawn up of all the English garrisons, and those marked with an asterisk were to be 'reduced entirely'. With this document, the fate of Mersea Fort was sealed. Orders were sent to Captain Burrell to disband his garrison and dismantle the fortifications. This was easier said than done, since it took some time to procure sufficient funds to pay off all the soldiers' arrears, while the owner of the land on which the fort stood, James Shirley of Clapham, objected to its demolition.
Over three succeeding centuries, Mersea Fort was gradually allowed to crumble into decay. In 1677 the Shirley family sold their land, including 'all that tenement called the Blockhouse'. This may be the fort itself, or possibly the house shown to the east of the fort on a map of 1656, and long since swallowed up by the sea. In 1710 the Blockhouse was described as 'much decayed, onely some pieces of ordenance without [gun] carriages'. However less than a century later, during the Napoleonic wars, the ruinous fort was once again called into service. A gun battery was built into its seaward wall, from which six 24 pounder guns could be fired on any hostile ships, and 60 islanders were conscripted to join the 'Sea Fencible' militia. But Napoleon was defeated, and Mersea Fort was once again forgotten. Unlike nearby forts at Landguard and Tilbury, it was never rebuilt and thus has avoided the fate of becoming a tourist attraction. Instead, as the earthern bulwarks sink slowly into the mud, they present a forlorn reminder of that brief moment in 1648, when Royalist victory in the second civil war might have turned the tables of history and saved the head of the doomed king, Charles I.
Most of the information was drawn from the Council of State proceedings recorded in the Commonwealth State Papers; Essex Historic Environment Records; articles
in 'Essex Review' and 'Essex Archaeology and History' and books such as the Victoria County History and Peter Kent's 'Fortifications of East Anglia'.
Article published in the Courier in two parts, 20 July 2011 Issue number 510 and 3 August 2011 Issue 511.