The Bow
During the middle ages bows were manufactured by bowyers, a craft guild which still exists today. The guild operated much like any other at the time, apprenticing boys and training them over a period of roughly seven years. The guild was and still is, a guarantee of quality for the trade of bow making.
Today bows can be made from all sorts of materials, even without any wood at all, which would seem fantastical to a medieval bowyer. Modern bowyers have incredibly efficient glues. This adhesive technology allows them to create laminated bows, with different types of wood selected for strength, flexibility and often it seems just for good looks. No such luxury for the medieval bowyer, he had no choice other than to build 'self' bows, made from a single stave of wood.
The premium wood for bow making in the middle ages was yew, and is still considered the best bow wood today by traditional bow makers. Ash, and other 'mean' woods, such as wych elm were also used, but yew was prized for its strength and flexibility provided by the tree's heart and sap wood. The photograph below clearly shows the definition between the heart and sap on a piece of yew. A piece of ash is also shown, popular too for making arrow shafts.
Below: in the top picture the redder heart wood is clear to see on the belly of a yew bow; this harder wood forms the greater part of the bow and resists compression, or squeezing when the bow is drawn. The bottom picture shows the creamier sap wood on the back of the bow, which is softer and resists the tension, or stretching when the bow is drawn. The central picture is a side view of the bow showing both natures of the yew.Thus when a yew bow is drawn, the heart and sap wood work together to resist the forces acting on the bow, creating a fine natural spring.
The ends of the bow limbs are fitted with nocks, the medieval word for notch. These are usually fashioned from animal horn, creating a tough and durable platform for the string groove. Nocks also help to protect the ends of the bow limbs from splitting under the force of the string, or being damaged if the limb tips are accidentally grounded or knocked against a hard surface. I have worked around many castles with my bows over the years, and it seems there is always something to bash the end of your bow against. The medieval bowstring was generally made using waxed linen thread.
The yew bow was often depicted in contemporary manuscripts and tapestries, and the artists must have had first hand experience of seeing the weapons close up, to be able to illustrate them so accurately. This 15th century image shows archers using very powerful yew bows. They are exact in detail if slightly exaggerated and out of proportion.
Arrows were many and varied in design but all intended to kill or do as much damage as possible. The shafts of war arrows were made by hand, splitting and planing wooden billets into shafts. Ash and poplar were widely used, and many other woods besides. Battle shafts were often 'bobtailed' or tapered back from the head to the nock. This meant that roughly 1/3rd of the shaft from the head end was thicker and less likely to break, and allowed for a heavier arrow head.