Most scholars agree that William the Conqueror certainly made use of the motte-and-bailey castle design in his conquest of England, using them to control a country that had not had much experience with them previously (Dawson para. 1). Most historians believe that the Normans’ rapid construction of castles in the aftermath of the conquest “was the most extensive and rapid castle building program in history” (DeVries & Smith 217). It seems like a difficult claim to believe considering most scholars cannot seem to provide a definite number of castles that were produced. However, it is understandable when one considers that it is currently estimated that over five hundred were built by 1087 (Gillingham 73). However, that was not the only contribution William made to castle history. He contributed to England’s transition from the motte-and-bailey castle to the rectangular keep (also called a donjon) by building some of the first keeps in Britain—the White Tower in London and Colchester Castle (DeVries & Smith 217).
The transition from motte-and-bailey castles rested partly on the advantages and disadvantages of the design. The motte-and-bailey castles were advantageous because they were easy to build, so “unskilled labor” could be used during the construction (DeVries & Smith 220). The fact that “on occasion they also seem to have played a strong role in stopping large armies” proved to be incentive enough for their construction (DeVries & Smith 220). As England saw, the motte-and-baileys could be rapidly constructed and used to maintain control over the surrounding land.
However, the motte-and-bailey castle had some disadvantages that became problematic as siege warfare developed. As a wooden structure, there was the potential problem that the castle could go up in flames due to an “internal domestic source” or a deliberate, “external, hostile action in time of war” (Lepage 37-38). In addition to being a fire hazard, the wood also required continual maintenance and proved ill-suited for heavy assaults (DeVries & Smith 220). The motte-and-baileys may have proved advantageous to the Normans who sought to quickly gain control of the newly conquered territory, but they were by no means invincible and—in many ways—soon became ill-suited for withstanding sieges. For example, castles constructed from stone were better suited to withstand both “fire and physical bombardment” (Jones 173).
The concept of using stone to build castles had existed prior to William the Conqueror’s keeps (DeVries & Smith 224). In fact, “the earliest now-surviving stone castles were built in France during the late tenth century” by Fulk Nerra, the Count of Anjou (Jones 172). These castles were—with the exception of Langeais—mostly stone versions of the motte-and-bailey (Jones 172). The only thing that really changed was the construction material resulting in circular shell keeps (Dawson para. 4). Overall, this stone version of the motte-and-bailey seems not to be very prevalent in England during this period (DeVries & Smith 229). Some say this is partly because “they lacked the strength and solidity of rectangular keeps” (Yarwood 48). Perhaps it was because the rectangular keep was much more massive in size. Whatever the reason, the “rectangular tower keep” was far more common (DeVries & Smith 229), and some say it was “the most striking legacy of Norman castle building” (Dawson para. 8).
It is important to note that this shift in design from the motte-and-baileys to rectangular stone keeps was not instantaneous or drastic (Lepage 38). Often the type of castle that was built depended heavily on the circumstances in question, like the amount of money the lord could afford to spend (Lepage 38). Those who could not afford to sculpt their castles out of stone had to rely on old-fashioned wooden ones (Lepage 46). Not everything about the motte-and-bailey design was immediately abandoned either, with some of the elements of the motte-and-bailey castle design still being preserved in the newer rectangular keep. For example, the primary focus for the castle defenders “was still based on the holding of the outer line of [defenses]” (Jones 172). These outer walls were just made of stone versus wood (Jones 172). Aspects of the motte and bailey clearly remained, considering how the keeps were built on the bailey (Toy 66).
England’s evolution from these stone versions of the motte-and-bailey to the more rectangular stone keep (or donjon) was fueled by a few factors. William was likely aware of the rectangular keep design because it “was used by the Normans in France from the beginning of the 11th Century” (Dawson para. 8). If wooden motte-and-bailey were constructed because that they could be constructed quickly, it makes sense that afterwards the more durable stone rectangular keep that began being built. Rectangular keeps certainly spread all over England during the twelfth century (Toy 66).
Another reason for the change in construction seems to have been a change in enemy. As time progressed, the main insurgents to the Norman kings’ rule were not the unruly peasantry but fellow Norman lords (Dawson para. 3). This is demonstrated by the chronicler Ordericus Vitalis who details a revolt led against William Rufus (William the Conqueror’s son) by Robert de Mowbray in his book The Ecclesiastical History of England and Normandy (17). He writes that:
The great body of the Normans who, becoming rich in England with wealth gained by the labours of others, were filled with arrogance, were still urged onward by the incentives of an insatiable avarice and pride. It was to them a source of envy and grief that William Rufus was distinguished for his courage and merit, and fearing no one, governed all his subjects with a firm hand. In their insolence they leagued together and formed a foul conspiracy against the king, and disregarding the fealty which they had sworn to their lord, fell into the disgraceful crime of treason. (Ordericus Vitalis The Ecclesiastical History of England and Normandy 17)
In response, William laid siege to Robert’s castle of Bamborough (Vitalis 19). This particular siege came to an end when “Robert de Mowbray, disgusted and wearied with the long blockade came out by night and attempting to pass from one castle to another fell into the enemies’ hands” (Vitalis 20). In later eras where royal authority was less secure, like Stephen’s rule, the reliance on castles increased as well (Dawson para. 3).
These incidents demonstrate that sieges were still underway. Unfortunately, “by the early twelfth century, siege tactics were well understood by most military commanders,” resulting in an increase in siege success (Jones 172). Castles naturally had to evolve in order to combat this new assault efficiency (Jones 172). This led to the development of designs like the rectangular keep or donjon, as it was also called (DeVries & Smith 229). Two examples of this design are demonstrated below by the keeps of Colchester Castle and Clitheroe Castle.

Sannse. “Colchester Castle, Front and SE Corner.” Wikimedia Commons, 21 May 2004, commons.wikimedia.org/wiki/File:Colchester_castle_800.jpg. Accessed 04 Dec. 2016.

Giel, Immanuel. “Clitheroe Castle 05.” Wikimedia Commons, July 2010, commons.wikimedia.org/wiki/File:Clitheroe_Castle_05.jpg.. Accessed 04 Dec. 2016.
The donjon “offer[ed] active defensive options by its elevation, as well as passive resistance as a place of last refuge” (Jones 172). Rectangular keeps were more impressive in size, with most keeps “cover[ing] an area more than 30 meters square” (DeVries & Smith 229-230). The keep’s sheer size and weight meant that it had to be constructed on the bailey (DeVries & Smith 230).
The keeps’ popularity was partially because they were well-suited defenses against the time period’s siege methods, which were fairly insufficient when compared with later developments (Lepage 54). These siege methods would gradually develop, and the castle’s design would evolve again along with it. However, during this time period, the current design coupled with adequate stores enabled the castle’s garrison to potentially “hold out for months, even a year and more” (Hindley para. 4). The evolution of castles from wooden structures to stone fortifications proved to be an important step “in the evolution of the power” (Lepage 45). This development contributed to a golden age in castle construction in later centuries where “the wealthiest would be able to build, confiscate, or dismantle castles according to their own interest and strategy” (Lepage 45).
Works Cited
Dawson, David. “The English Castle, Part #2.” Britannia History, 2007, www.britannia.com/history/david2.html. Accessed 26 Nov. 2016.
DeVries, Kelly, and Robert Douglas Smith. “Chapter Eight: Motte-and-Bailey Castles.” Medieval Military Technology, 2nd ed., University of Toronto Press, 2002. pp. 211-222.
DeVries, Kelly, and Robert Douglas Smith. “Chapter Nine: Stone Castles.” Medieval Military Technology, 2nd ed., University of Toronto Press, 2002. pp. 223-260.
Giel, Immanuel. “Clitheroe Castle 05.” Wikimedia Commons, July 2010, commons.wikimedia.org/wiki/File:Clitheroe_Castle_05.jpg. Accessed 04 Dec. 2016.
Gillingham, John. “An Age of Expansion c. 1020-1204.” Medieval Warfare: A History, edited by Maurice Keen, Oxford University Press, 1999, pp. 59-88.
Hindley, Geoffrey. “Chapter Seven: Attack and Defense.” Medieval Sieges & Siegecraft. NewYork: Skyhorse Publishing, 2009, EBSCO Host, web.a.ebscohost.com/ehost/detail/detail?nobk=y&sid=a1f019df-6781-4b9a-9888-dfa51b59e708@sessionmgr4008&vid=44&hid=4204&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ==#AN=648279&db=nlebk. Accessed 02 Nov 2016.
Jones, R.L.C. “Fortifications and Sieges in Western Europe c. 800-1450.” Medieval Warfare: A History, edited by Maurice Keen, Oxford University Press, 1999, pp. 163-185.
Lepage, Jean-Denis, G. G. “Chapter Two: The Revival of Military Architecture from the 10th to the 12th Centuries.” Castles and Fortified Cities of Medieval Europe: An Illustrated History. McFarland & Company, Inc., Publishers, 2002. pp. 28-106.
Sannse. “Colchester Castle, Front and SE Corner.” Wikimedia Commons, 21 May 2004, commons.wikimedia.org/wiki/File:Colchester_castle_800.jpg. Accessed 30 Nov. 2016.
Toy, Sidney. “Chapter VII: Rectangular Keeps or Donjons.” Castles: Their Construction and History. 1939. Dover Publications, Inc., 1985. pp. 66-81.
Vitalis, Ordericus. The Ecclesiastical History of England and Normandy. Translated by Thomas Forester, London: Bohn, 1853. E.J. Pratt Library, University of Toronto, Archive, archive.org/details/ecclesiasticalhi02ordeuoft. Accessed 26 Nov. 2016.
Yarwood, Doreen. “Chapter II: Norman and Early English Gothic 1066-1275.” The Architecture of England: From Prehistoric Times to the Present Day. London: B.T. Batsford LTD, 1963. pp. 29-73.