The basic design
A motte and bailey castle had two parts. The motte was a mound of earth, sometimes natural and sometimes built up, with a flat top. A wooden tower or palisade stood on this summit. The bailey was an enclosed yard at the foot of the mound, protected by a ditch, a bank and a timber fence. A bridge or ramp usually connected the two.
The mound gave height, which helped lookouts and defenders. The bailey held what a household needed day to day: a hall, stables, workshops, storage buildings, a kitchen and sometimes a chapel. If the bailey fell, those inside could retreat to the motte tower for a last stand. Sometimes there were two baileys, and some mottes stood within existing earthworks.
How one was built
Construction was labor-intensive but required few specialist skills. Workers dug a ditch around the site and piled the excavated soil in the center to form the mound. Layers of earth, clay and stone might be packed down in turn to give stability. A timber tower was then built on the top, and a palisade of stakes was set along the ditch banks. Where good natural hills existed, builders could save work by shaping them rather than starting from nothing.
How long a motte took depends on its size and the workforce, and estimates vary. Smaller examples may have been raised in a matter of weeks or months with local labor, which was one reason they were attractive. Larger ones took far longer. Because the work relied on forced or paid local labor, the burden often fell heavily on people living nearby.
Why the Normans used them
The form is strongly associated with the Normans, and it appears in Normandy and neighboring parts of France before 1066. Its quick, cheap construction suited conquerors who needed to secure ground fast. Chroniclers and the Bayeux Tapestry depict mottes with timber towers in the years of the conquest, and after the Battle of Hastings, William’s followers built many such castles. Some accounts claim that William’s army brought a prefabricated wooden fort in 1066, but how reliable this is cannot be settled with certainty.
In the generations after the Norman takeover of England, hundreds of mottes were raised across the kingdom. Historians count them in the hundreds, with the exact number depending on how doubtful sites are treated. Norman lords also used the design in Wales and later in parts of Ireland and Scotland, where Anglo-Norman settlement carried it. The design was not exclusive to the Normans, however, and similar earthwork forts existed elsewhere in Europe.
Strengths
- Speed and low cost. Local soil and timber did most of the job.
- Height. The mound gave a view over the surrounding land.
- Flexibility. The layout could adapt to the site, and the bailey could be enlarged.
- Visibility. A mound dominated the landscape, advertising the arrival of a new lord.
Weaknesses
The main weakness was the building material. Timber rots, and over time the tower and palisades needed regular repair. Wood also burns, and attackers could use fire arrows or torches. The mound’s soil could settle or erode, and a heavy stone building could not simply be added on top of freshly piled earth, because it might sink or crack.
Against a determined assault by a large army with equipment, a motte and bailey was vulnerable. Its purpose was usually to hold a district against local resistance rather than to withstand a royal siege.
Ringworks and variants
Not every early castle had a motte. A ringwork was a simple enclosure with a bank and ditch and a timber palisade, with no raised mound. Some sites started as one form and changed to another. Historians use these terms as convenient labels, but real sites were varied.
What happened next
Many mottes were abandoned once the immediate need passed, especially where the lord moved to a better location or built a manor house instead. Others were rebuilt in stone. A common solution was the shell keep, in which a ring wall was built around the top of the mound, sometimes replacing the timber palisade. Clifford’s Tower in York stands on a motte and is a later stone structure on an earlier timber fortification. Where a stone keep was desired, builders often chose to place it beside the mound rather than on it, or to strengthen the foundation first.
Windsor and a number of other major castles still show their motte origins, though the buildings on top are far later. Elsewhere only a grassy mound and ditch survive, and these earthworks are an important source of evidence, since many have been little disturbed.
Reading the landscape
Visitors can often spot a motte today as a steep, flat-topped hill beside a church or village, sometimes with a ditch around it. Place names and local tradition sometimes give clues, but caution is advised, since natural hills and later features (such as landscape gardens or windmill mounds) can look similar. Archaeology, documents and survey are needed to confirm what a site was.
Motte and bailey castles reflect a particular moment, when rulers needed strongpoints quickly, using the materials and labor at hand. Their later replacement by stone shows how castle building developed once settled lords had time and money to invest in lasting defenses.