Upnor Castle was built in the mid sixteenth century to protect the Naval dockyard at Chatham. In 1667 the fortification fought a battle with a Dutch Squadron as they penetrated the River Medway but, despite putting up a strong resistance, it was unable to prevent the destruction of a significant portion of the English Fleet nor the capture of the flagship, the Royal Charles.
From the mid-sixteenth century onwards, ships of the Royal Navy started making regular use of the River Medway. The rock free riverbed and sheltered waters offered the ideal location for ships to spend extended periods at anchorage or to be pulled aground for repairs. As use of the river increased, shore facilities were developed starting with a storehouse at Gillingham and this small footprint soon expanded into Chatham Dockyard. During the early decades of Queen Elizabeth I's reign, during which the ships of the Royal Navy were largely laid up, 23 vessels were anchored at Chatham. As the overall Fleet only numbered between 24 and 26 ships, this represented a significant concentration of the country's naval assets. However, coastal defences along the river were fairly lean. Most of the ships were anchored in the vicinity of Rochester bridge, which was overlooked by Rochester Castle, but that medieval structure was obsolete and had no means of defending the ships. Further downstream was Queenborough Castle which provided some protection to Sheppey but could do little against enemy vessels sailing along the River Medway. A small Tudor blockhouse, built during the reign of Henry VIII, had been constructed at Sheerness but was small and ineffective against a determined attack. Accordingly in 1559, the Government of Elizabeth I commissioned a coastal defence fortification at Upnor.
Upnor Castle was positioned to control a bend in the River Medway upstream of the main anchorages and facilities at Chatham. Any enemy vessel attempting to attack the dockyard needed to close to Upnor and pass the castle site. Furthermore, the new fortification was positioned with a good view of the river as it was aligned with St Mary's Creek. Sir Richard Lee was commissioned to design the new fort but, as he was fully engaged building the new town defences at Berwick-upon-Tweed, he delegated the task to his deputy, Humphrey Locke. The castle at this time consisted of an angle bastion that overlooked the river and carried the main anti-ship weapons. To its rear was a two storey building hosting further guns, accommodation facilities, magazines and administrative space. Stone was robbed from Rochester Castle to aid in its construction. Work on the castle continued through to 1567.
As Elizabeth I's reign progressed, relations with Spain deteriorated and fears grew that the River Medway would suffer an attack from the large Spanish forces operating from their bases in the Netherlands. In 1575, Swaleness Fort was erected to protect the mouth of the River Medway (a plan to build a further fortification Sheerness or the Isle of grain was rejected due to concerns an attacking force could bypass it by sailing up the Swale). Enhancements were also made at Upnor; St Mary's Creek was fouled by a timber palisade and a chain was installed running between the castle and the opposite bank (this was later moved downstream).
Upnor Castle underwent a substantial rebuild between 1599 and 1601. The Water Bastion was modified to take heavier weaponry and a timber palisade was installed in front of it to provide protection from enemy landing parties and to stop ships coming alongside the bastion at high tide. A gatehouse and curtain wall were also added with two new structures, the North and South Towers, overlooking the waterfront and enabling flanking fire along a ditch that fronted the wall. Two earthwork forts, Bay Sconce and Warham Sconce, were also added at this time.
Upon the outbreak of the seventeenth century Civil War, Upnor Castle remained in Crown ownership. However, the region and navy were controlled by Parliament and accordingly the castle and its sconces were surrendered without a fight. It saw no action during the first conflict and its sole military use was as a prison for Royalist officers. However in 1648, during the Second Civil War, Upnor Castle was briefly seized by Royalist forces as part of a wider uprising across Kent. The rebellion was quickly suppressed and the castle recovered. Some repair work was undertaken in 1653 after an (accidental) fire in the Gatehouse. Brick, rather than stone, was used for this work giving the gatehouse its distinctive appearance.
The latter half of the seventeenth century saw Britain embroiled in a number of wars with Holland. Like England, the Dutch were a maritime nation but tended to be third party traders picking up wares from one nation and transporting them to another. In 1651 Cromwell approved the first of the Navigation Acts which mandated that all imported goods must be carried on English ships or those of the exporting nation. This excluded the Dutch and led to the First Anglo-Dutch War (1652-54). A number of battles ensued and the war ended when both nations were exhausted from the conflict. However, following the Restoration of the monarchy, Charles II also promoted protectionist policies that led to the Second Anglo-Dutch War (1665-67) and Upnor Castle saw action during this conflict.
In June 1667, a Dutch Squadron under the command of de Ruyter arrived off the Isle of Sheppey. His forces landed at Sheerness and burnt the half-built fortification being constructed on the headland. He then moved his fleet into the River Medway. George Monck, Duke of Albemarle took charge of the defences and ensured the harbour chain was rigged and hastily built two earthwork batteries at Hoo Ness and Gillingham. On the morning of 12 June 1667 the Dutch forces smashed through those defences and seized the Royal Charles, the English flagship, and burnt other ships anchored in this part of the river. As the tide turned the Dutch went to anchor and Albermarle feared the next day they would proceed further inshore, passing Upnor and burning the rest of the Fleet at Chatham and Rochester. Overnight the Duke hastily erected Middleton Battery adjacent to Upnor Castle. On 13 June 1667 the Dutch pushed further upstream and came under intense fire from Upnor Castle and Middleton Battery. Both had been augmented by additional troops rushed into the area by Monck. Samual Pepys wrote about the action “I do not see that Upnor Castle hath received any hurt by them though they played long against it; and they themselves shot till they had hardly a gun left upon the carriages, so badly provided they were”. Despite the fierce fire from the castle, the Dutch successfully burnt more Royal Navy ships before they withdrew to Queenborough. They remained there for several days before they finally withdrew. The humiliation of the attack led Britain to end hostilities at the Peace of Breda.
The humiliation at Medway prompted substantial upgrades to coastal defences around key military ports. In the Medway a vast new bastioned facility, Garrison Point Fort, was built to protect the guns at Sheerness. Upstream two new outposts - Cockham Wood Fort and Gillingham Fort - were also built. All three were designed by the King's chief engineer, Sir Bernard de Gomme, who ironically was a Dutchman! As the size of both the navy and the ships within it increased, meaning more vessels anchored in the main river channel, further gun batteries were built at Hoo Ness and on the Isle of Grain. All these new facilities made Upnor Castle redundant and by the late seventeenth century it had been relegated to a stores complex and magazine. The castle was modified accordingly with the gun platforms on the roof of the main building removed. It continued to be used as a magazine until 1827 and thereafter served in various roles until formally recognised as a museum in 1945.
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Upnor Castle is a well preserved Elizabethan coastal defence fort that was later expanded.
Medway Defences. The first fortification was Rochester Castle, built at the crossing point over the river. In the mid-sixteenth century Chatham dockyard was established prompting construction of Upnor Castle. Later further defences were built ever further west and the eighteenth and nineteenth century saw landward defences constructed.
Upnor Castle Layout. The original castle consisted of the Water Bastion and Main Building. These structures were augmented by curtain wall, gatehouse, north tower, south tower and the palisade circa-1600.
Upnor Castle. The castle was built on the banks of the River Medway with the bulk of its armament installed on the low bastion just above the wooden palisade.
Water Bastion. The Water Bastion had nine embrasures with six facing downstream and three upstream. The rounded parapet was intended to deflect enemy shot. The wooden palisade was installed circa-1600 to provide better protection against an enemy landing party attempting to storm the castle.
Castle Exterior. The outer curtain wall was added as part of the modifications made between 1599 and 1601. The upgrades included the gatehouse and the North and South Towers.
Outer Gatehouse. Originally the gatehouse was accessed via a drawbridge. The brick additions were added around 1625 when the gatehouse was rebuilt after a fire.
Gatehouse. Seen from inside the courtyard.
Main Building. The first floor of the main building was used for stores. The windlass that was used for hoisting stores down to the Water Bastion cane be seen on the right.
River Medway. The castle had a clear field of fire over a bend in the river and the low lying land of St Mary's Creek gave good visibility of approaching enemy ships.