William had to to secure his foothold in southern England, and required a means of ruling the rest of his new country.
As a result, from 1066 to 1087 William and the Normans built nearly 700 motte and bailey castles across England and Wales.
These castles, which were relatively quick to build, but difficult to capture, formed a key part of William’s strategy for controlling his new domain.
The origins of the motte and bailey
Popular in Europe from the 10th century, some historians emphasise the military and defensive capabilities of motte and baileys, especially in repelling Viking, Slavic and Hungarian raids into Europe.
Others explain their popularity by arguing they supported the feudal social structures of the period: they were built by feudal landowners to protect their property.
Regardless, the name ‘motte and bailey’ derives from the Norman words for ‘mound’ (motte), and ‘enclosure’ (bailey). These words describe the most important aspects of the castles’ design.
How did they build them?
The motte, or mound, on which the main keep was built was made of soil and stone. Research on Hampstead Marshall’s motte and bailey shows that it contains over 22,000 tons of soil.
The earth for the motte was piled in layers, and was capped with stone after each layer to strengthen the structure and allow faster drainage. Mottes varied in size, ranging from 25 feet to up to 80 feet in height.
Ideally, the mound would have steep slopes, to prevent attackers from assaulting on foot. Additionally, a ditch would have been dug around the bottom of the motte.
The keep which stood on top of the mound was often just a simple wooden tower, but on larger mounds, complex wooden structures could be built.
The bailey, an enclosure of flattened land, lay at the bottom of the motte. It was connected to the keep on the motte by a wooden flying bridge, or by steps cut into the motte itself.
This narrow, steep approach to the keep made it easy to defend if attackers breached the bailey.
The bailey was surrounded by a wooden palisade, and a ditch (called a fosse). If it was possible, nearby streams were diverted into the ditches to produce a moat.
The outer edge of the bailey’s palisade were always within bowshot of the keep, to ward off attackers. A few baileys, like that of Lincoln Castle, even had two mottes.
The strongest mottes could take up to 24,000 man hours to build, but smaller ones could be completed in only 1,000 man hours. A motte could thus be raised in a few months, compared to a stone keep, which might take up to ten years.
From Anjou to England
The first motte-and-bailey castle was built at Vincy, Northern France, in 979. Over the following decades the Dukes of Anjou popularised the design.
William the Conqueror (then the Duke of Normandy), observing their success in neighbouring Anjou, began to build them on his Norman lands.
After he invaded England in 1066, William needed to construct castles in large numbers. They demonstrated his control of the population, ensured protection for his soldiers, and solidified his rule in remote parts of the country.
After several uprisings, William subjugated northern England in a campaign called the ‘Harrying of the North’. He then built significant numbers of motte and bailey castles to help maintain peace.
In northern England and elsewhere, William seized land from rebellious Saxon nobles and reassigned it to Norman nobles and knights. In return, they had to build a motte and bailey to protect William’s interests in the local area.
Why the motte and bailey was successful
A major factor for the success of the motte-and-bailey was that the castles could be hastily and cheaply constructed, and with local building materials. According to William of Poitiers, William the Conqueror’s chaplain, the motte and bailey at Dover was built in only eight days.
When William landed in modern-day Sussex, he had neither the time nor materials to construct a stone fortification. His castle at Hastings was eventually rebuilt in stone in 1070 after he had solidified his control over England; but in 1066 speed was the priority.
Also, in the more remote west and north of England, peasants could be forced to construct the castles, as the structures required little skilled labour.
Nevertheless, owing to the importance of stone structures for defensive and symbolic reasons, the motte and bailey design declined a century after William’s invasion. New stone structures could not be easily supported by mounds of earth, and concentric castles eventually became the norm.
Where can we see them today?
It is harder to find a well-preserved motte and bailey compared to other types of castles.
Predominantly made of wood and soil, many of those built under William the Conqueror decayed or collapsed over time. Others were burnt down during later conflicts, or were even converted into military defences during the Second World War.
However, many motte and baileys were converted into larger stone fortifications, or adopted into later castles and towns. Notably, at Windsor Castle, the former motte and bailey was renovated in the 19th century, and is now used as an archive for royal documents.
In Durham Castle, the stone tower on the old motte is used as student accommodation for members of the university. At Arundel Castle in West Sussex, the Norman motte and its keep now form part of a large quadrangle.
At Hastings Castle in East Sussex, close to where William the Conqueror defeated Harold Godwinson, the ruins of the stone motte and bailey still stand atop the cliffs.
Elsewhere in England, large, steep-sided mounds reveal the former presence of a motte and bailey, such as in Pulverbatch, Shropshire.