Dover Castle is located at the shortest crossing point on the English Channel in Dover, Kent. The castle started life as an Iron Age Hillfort, then becoming a Roman Fortress, later still an Anglo Saxon Burg and then in 1066 the Normans built a Motte and Bailey castle on the site. This was replaced in the 12th century by a great stone keep built by King Henry II.
The oldest building on the site is the Roman lighthouse, an octagonal tower built with eight stepped stages to about 80ft high, which sits next to the restored Saxon church on the highest point of the castle. A large bank surrounds them which dates from the 13th century and it is believed that this is the area where William the Conqueror built his original castle. The Romans developed Dover as a port in the later half of the first century. They needed a way to guide ships across the channel so built three lighthouses. One was built in Boulogne in France and the other two in Dover on the highest ground possible either side of the harbour. The lighthouse at Drop Redoubt on the Western Heights was destroyed and only the foundations remain. The one at Dover Castle survived, being put to various uses over the centuries. In the early 14th century the tower top was rebuilt as a bell tower for the Saxon church and walls refaced by Humphrey, Duke of Gloucester.
The Saxon Church, St Mary in Castro dates back to at least to the 10th century. It was part of an Anglo-Saxon burgh, a defended or fortified settlement which was built on the hillfort utilising the defensive structure of the hillfort. It was built partly from Roman tiles and other building materials in a cross shape plan. The grave yard was to the south of the church. The church was modified by the Normans sometime in the 12th century. The church fell into disuse and became derelict. By the early 18th century it was used as a fives court, a game where a ball is propelled against a wall in a court using gloved or bare hand as if they were a racquet. During the Napoleonic Wars, between 1803 to 1815 it was used to store garrison coal. By the 1860's it was roofless and crumbling. But the church was saved, much like most churches in the late 1800's it was restored. The architect Sir George Gilbert Scott undertook the restoration in 1862 but it was William Butterfield who completed the tower and added the mosaic decoration in the nave. The surrounding bank was once topped with a mediaeval curtain wall which linked Pencesters tower to Peverills tower with Coltons gateway in between. This was removed in 1772 but Coltons Gateway survived.
The first Norman castle at Dover was built by Duke William of Normandy in November 1066 when his army advanced on Dover to strengthen his position in the country. Dover surrendered and William spent eight days building his prefabricated wooden motte and bailey castle at Dover before he moved onto Canterbury. This castle was attacked soon after it was built when Count Eustace of Boulogne landed to strengthen the Kent rebels.
King Henry II became king in 1154 and set himself on a rebuilding program of England's most important castles. At first Dover Castle had minor improvements made to the existing fortifications, but it wasn't until 1179 that the castle got a major overhaul to what we see today. King Henry II died in 1189 with the castle incomplete. King John ignored the castle until he lost Normandy in 1204 when he then spent a considerable amount of money to complete the castle. Even with the money it was not until 1215 that the castle could be easily defended.
In May 1216, Prince Louis landed at Thanet to support the Kings barons who were rebelling against King John. By the autumn only Windsor and Dover castles in southern England were commanded by the King. The castle was set upon but Hubert de Burgh and his knights defended well forcing the barons to lay siege to the castle. French miners tunneled under the eastern of the two gate towers finally causing it to collapse and the French forces poured into the castle. Again Hubert de Burgh and his garrison fought the French forcing then back through the breach. A truce was called early in the autumn but in October King John died at Newark Castle and his son, Henry III, was proclaimed king. At Dover the local truce held into the spring of 1217, but then in May Louis returned to resume siege, he needed to capture the castle so as to secure his supply lines into the country. Three days later the French were defeated at the Battle of Lincoln, which signified the end of the war. Dover Castle, after a year of sieges and truces, remained un-captured although badly damaged.
The castle was modified as the French had shown the weaknesses in the design, the northern gateway, so nearly the castle's downfall, was blocked solid. In the moat beyond, engineers constructed St John's Tower which in turn overlooked a new spur or outwork to the north, designed to allow the garrison a better command of the high ground. The north gateway was replaced by the formidably powerful Constable's Gateway on the western side of the castle. Difficult anyway for an attacker to approach because of the sloping ground, the clustering of no less than six towers here made it one of the most powerful gateways in England. A secondary entrance, Fitzwilliam's Gateway, was built on the eastern side of the castle. The outer curtain wall was completed from Peverel's Tower to the cliff edge, and a massive earth bank was constructed round the church and pharos. Initially this bank was topped by a timber palisade but this was replaced by a stone wall in the 1250s. The castle had reached the peak of its medieval power with its formidable series of concentric defences.
By the 1500's the castle was becoming obsolete, canons were becoming more powerful and increasing in size. The castle has survived due to location rather than design.
The Civil War ,in 1642, saw Dover town sided with Parliament while the castle garrison supported the king. That August a small party of townsfolk daringly scaled the cliffs, surprised the garrison and captured the castle, which fell with hardly a shot fired. At the Restoration of the monarchy in 1660, grandiose plans to quarter a substantial garrison in the castle were eventually reduced to the installation of seventeen gunners, probably based at Moat's Bulwark, the sixteenth-century gun battery at the foot of the cliffs. The castle itself remained largely uninhabited, the keep being used to house prisoners-of-war for a number of years at the end of the seventeenth century.