How Castles Work

The Decline of Castles

Windsor Castle is an official home of Queen Elizabeth II.
Julian Herbert/Getty Images

After the 16th century, castles declined as a mode of defense, mostly because of the invention and improvement of heavy cannons and mortars. This artillery could throw heavy cannonballs with so much force that even strong curtain walls could not hold up.

Eventually, the medieval castle gave way to fortified cities (almost a reversal of history) and forts (like those seen in Colonial times in North America). Instead of high brick or stone walls, these forts had broad earthen ramparts with wooden or stone palisades on top. The idea was that thick layers of dirt would absorb the impact of cannon fire. Also, these fortifications were easier and faster to build than castles. During the American Revolution at the Battles of Bunker Hill and Dorchester in Boston, the American army fortified their positions almost overnight.


Castles Today

In their heyday, castles were found throughout Europe and the Middle East. Most were in Europe -- there were 10,000 in Germany alone. Although improvements in military technology and the expense of castle construction brought the age of castles to an end, some were built so well that they survive to this day. Some castles are merely ruins, while others have been restored. Surviving castles have been used for many purposes:

  • Some castles, like Windsor Castle, were restored during the 18th and 19th centuries and serve as homes for wealthy or noble families.
  • Historical sites and museums, like the Tower of London, Warwich Castle and Bodiam Castle in England, educate and entertain the public about the Middle Ages.
  • Some castles have been converted into hotels, like Thornbury Castle in England and La Rocca di Monteggiori in Italy.

A number of wealthy industrialists in the 20th century built homes that were designed like castles. Although many of these homes are designed more like palaces than true castles, they are architecturally magnificent and visited by many tourists each year.

  • Publisher William Randolph Hearst built Hearst Castle in California.
  • Hotel magnate George Boldt built Boldt Castle on the St. Lawrence River in upstate New York.
  • Toronto industrialist Sir Henry Mill Pallatt built Casa Loma in Ontario.

For more information about castles, check out the links below.

Related HowStuffWorks Articles

More Great Links


  • Castles in Shropshire. "Visiting Castles -- What to look for."
  • Castles of Britain.
  • Castles of the Middle Ages.
  • Dawson, David. "The English Castle." Britannia HistoryPart 1. 2. 3.
  • Donnelly, MP And D Diehl, "Siege: Castles at War", Taylor Publishing Company, 1998
  • Gibson, J, "Anatomy of the Castle", MetroBooks, 2001
  • Gravett, C, "The History of Castles", The Lyons Press, 2001
  • Himeji City, Japan, "Himeji Castle." english/himeji/node49.html#SECTION00091000000000000000
  • Kaufmann, JE and HW Kaufmann, "The Medieval Fortress", Combined Publishing, 2001
  • Life in a Medieval Castle.
  • Macaulay, D, "Castle", Houghton Mifflin Company, 1977
  • Morris, Marc. "Castle," Channel 4.
  • NOVA Online, "Medieval Siege."
  • Project Guedelon - Google translation of the original French site.
  • Warwick Castle.
  • Yahoo News, "French craftsman build medieval castle." france_building_a_castle