Castle – a type of fortified structure built in Europe and the Middle East during the Middle Ages by nobility. A castle is usually the private fortified residence of a lord or noble.
Castles originated in the 9th and 10th centuries, when territory was divided among individual lords and princes. These nobles built castles to control the area immediately surrounding them, and were both offensive and defensive structures; they provided a base from which raids could be launched as well as protection from enemies. Although their military origins are often emphasized, the structures also served as centers of administration and symbols of power.

Similar but different from
- palace – not fortified
- fortress – not always a residence for nobility
- fortified settlement – a public defense
What’s the problem?
How much protection is enough when you live in Europe in the 10th century? Some of the earliest castles were pretty basic. In the next 900 years many improvements were made in both effectiveness of the defenses and the comforts for the residents.

- Ask – During this period, there were no big governments or police, so wealthy people built castles to protect their families and their land. The intruders were armed with bows and arrows and swords. Cannons came much later. What was a minimum defense? What could be built with the materials and tools available?
- Imagine – As the intruders became a bigger threat, castle builders added additional defenses?
- Design, Build – Limiting access to the castle was one way to provide more security. Drawbridges and elaborate gates were created. How were the simple machines adapted for use in castles?
- Improve – Technologies and construction methods improved over time. How did this alter castle defense designs?

That’s engineering
- Portcullis – (from the French porte coulissante or gliding door) is a latticed grille made of wood, metal or a combination of the two. Portcullises fortified the entrances to many medieval castles, securely closing off the castle during time of attack or siege. Each portcullis was mounted in vertical grooves in castle walls and could be raised or lowered quickly by means of chains or ropes attached to an internal winch.
Engineering ideas
- fortification, moat, tower, winch
Do It
Challenges for you to work on…
- Make this hydraulic drawbridge (video 0:33)
- design a modern day castle. What would you defend against? Where would it be located? How would it be constructed? What defenses would your castle have?
- Review the online video Mindcraft tutorials for create a portcullis. Compare the finished structures and functionality.
Learn more…
- Castles.org – collection of descriptions of castles, mostly in Europe. Unfortunately many pictures are missing, but the information is good.
- How Castles Work – where castles came from, how they were constructed, how they were used, how they were attacked and defended, and what became of them.
- 29 Gorgeous Castles From Around The World – great images, lots of detail
- Project-Based Engineering for Kids – lots of great projects, low cost materials, easy to follow instructions with pictures, videos