Welcome to our next monthly installment of Digging Deep blog post, where we will round up and finish off everything we discussed in our posts this past week on Facebook! This week we explored castles in the United Kingdom- how were they made, and what were they made of!

Let us first start by exploring what castles are for in the first place. A castle was a powerful image that had a profound impact on the landscape- they were for military defense and protection, to reinforce status and social order, power, land consolidation, and for economic value. Castles were introduced in Great Britain and Ireland following the Norman invasion of England in 1066, and continued to grow in military sophistication and comfort during the 12th century. In Ireland and Wales, castle architecture continued eilean donan.jpegto follow that of England, later moving towards the use of smaller tower houses. A classic example of a tower house is Eilean Donan, made famous for being the scenic backdrop for many films, including the first Highlander film and Elizabeth: The Golden Age.

By the 14th century castles were combining defenses with luxurious, sophisticated living arrangements and heavily landscaped gardens and parks. By the 15th century only a few were maintained for defensive purposes. A small number of castles in England and Scotland were developed into Renaissance Era palaces that hosted lavish feasts and celebrations amid their elaborate architecture. Such structures were, however, beyond the means of all but royalty and the richest of the late-medieval barons. Although gunpowder weapons were used to defend castles from the late 14th century onwards it became clear during the 16th century that gunpowder would change the game of war. In the widespread civil and religious conflicts across the British Isles during the 1640s and 1650s, castles played a key role in England. Modern defenses were quickly built alongside existing medieval fortifications and, in many cases, castles successfully withstood more than one siege.

Initial Anglo-Saxon building in the UK cannibalized brick, tile, and stone from Roman buildings for construction until a more systematic industry of stone quarrying was instigated in the 11th and 12th centuries. Due to the varying geology across the UK, many of the building styles and traditions that developed over these periods were directly influenced by the kinds of rock available locally for building. Archaeological excavations of many castles have found temporary structures and workshops surrounding great hearths for forging and Lime kilns for lead and stone tile used on roofs. These can all be seen at Castle Sandal in West Yorkshire, when the castle was converted from a wood structure to a stone structure.

Masons were responsible for the building of the majority of the castles built in the UK. They often lived a nomadic lifestyle, traveling from town to town looking for work. They would often apprentice as young children, and if talented enough would one day become a Master Mason. Masons would usually have a contract with a local Lord, who would provide the funds for the building materials and the man power for the construction. Construction of a castle would also require carpenters and blacksmiths. Blacksmiths would sharpen the masonry tools every three days, and carpenters would build the scaffolding. It was hard work, and some projects would take most of a lifetime to complete. They used simple tools, consisting most of a mallet, chisel, and straight edge. Chisels would come in varying sizes and shapes, depending on their function and purpose. Trowels were also used to Blacksmith_working.jpgplace mortar around the stone to secure them in place. These hand tools do not seem like much, but it is amazing to see what is was that they built and how it has stood the test of time. Every mason would have a different mark that they would chisel into stone blocks and walls, almost like an early type of ‘quality assurance’ that they gave that structure or stone their seal of approval. They were apart of a huge and widespread industry, that is one of the worlds oldest trades in recorded history.

Every castle built during the Medieval period was uniquely built depending on several considerations, such as the terrain it was built on, the surrounding landscape, it’s overall purpose, the number of people it would support, and the wealth of the Nobles or Royalty who were building it. Most castles were usually built from a visual vantage point, such as a hill or mountain. UK geology has many natural features such as this in the landscape, such lindisfarne castle.jpgas Lindisfarne Castle pictured here. Castles also usually included an outer wall, a second line of defense, an inner wall, and a keep. Masons would draw a floor plan based on their extensive knowledge and needs of their employer, and get to work.

One important thing to have nearby when building a castle, would be a quarry from which to source this stone for masonry. Lords, Barons, and even Kings would often fight over such valuable resources. Since the cost of importing stone was so high, builders often used what was immediately available geologically, be it chalk, pebbles, limestone, or sandstone. Through time, as structured were assembled and destroyed, builders would also recycle already cut stone for new construction as well. Pictured to the rightwe have Dunnottar Castle in North East Scotland. Like most castles, donnottar.jpgDunnottar was a ‘work in progress’ and was added to over many years with many building materials. The rock the Castle sits upon was forced to the surface 440 million years ago during the Silurian period. A red rock conglomerate with boulders up to 1m across known as Pudding Stone is incredibly durable. The Highland rock pebbles and cementing matter is so tough that faults or cracks pass through the pebbles themselves.

In the UK, three of some common building materials aside from those mentioned above, especially in Scotland were Carboniferous Limestone, Red Sandstone, and Granite. First up is Carboniferous Limestone, found in the Midlands of Scotland, a sedimentary rock composed of grains of marine organisms. Next is Sandstone, commonly seen in the city of Edinburgh today, a sedimentary rock that consists of quartz and feldspar. Last but not least is Granite, found in the rocky Northern Scotland and used for building in Aberdeen. Limestone, Sandstone, and Granite are still sourced and used today for modern buildings just as they were for the Medieval structures that still linger in the landscape today.

A great example of a castle built from locally sourced sandstone is Carlisle Castle in DSC_0423England. Occupying a 4 acre piece of land, the castle is mostly constructed of grey and red sandstone, and its initial construction began in the 12th century. It is believed that the Romans initially quarried the Sandstone in the local area, but evidence of it has since been destroyed in the wake of massive removal for building since the Medieval period. Sandstone is
light, and easier to transport, yet durable enough for construction. However, over time gravity causes it to
settle, which might explain why many sandstone castles have needed reinforcement and constant upkeep over the centuries. Carlisle Castle was initially built to act as a home base for an invasion of Scotland, but became famous for acting as a prison for Mary Queen of Scots.

If you have found yourself particularly interested in any of the specific areas we have been talking about in this blog post, check out the British Geological Survey website to learn more about the geologic makeup of the continent. They have a complete analysis of the bedrock geology which is fascinating!

We have learned a lot about how castles were built in the UK through the fields of archaeology and geology, but that is not enough for some! In England there exists one of the world largest ‘experimental’ archaeological sites, Guédelon, where a 25 year project started in 1997 to build a castle using only Medieval technology and resources is well underway. Sometimes, we can learn the most by trying to actually ‘do’. Recreation using the same tools and techniques will often result in an archaeologist encountering the same dilemmas that a mason in the Middle Ages might have encountered. If this sounds interesting, please check out the link above if you would like to continue your journey and learn more about how to build castles! They also have a wonderful clip about how masons would mark out lines for walls or building features that you can watch by clicking here.

Thanks for joining us this week, and we will hopefully see you back on our page soon!

Jamie Erickson


2 thoughts on “British Castles: How Were they Made and What were they Made of?

  1. I Learn a lot from this informative site. I am a Micronesian and the materials we use for consftruction in our islands are primarily basalt rocks, sands, coral stones, and of course foreign lumbers. For building local houses we used trees that grew in our mangrove forests and used palm-like leaves for the thatched roofs. Our ancient royal palaces were mainly made of huge basalt rocks that were carved into long and rectangular shaped blocks. All of these blocks were stacked on top of each other to form a big rectangular wall on all four sides of the structure. Of course the top were completed with thatched-roofs which did not withstood the test of time. This is why I’m very interested in learning about the castles for they withstood the test of time. It’s truly magnificent.


  2. One of my dreams in life is to visit one of the castles in the UK. I hope that someday I can travel beyond our pacific horizon to see larger continents and countries beyond our horizon. We still live like our ancestors in our confined islands in Micronesia. Actually I’m from the island of the sleeping lady which is called Kosrae Island. The island is gradually awakened but at a very slow pace.


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