Date: about 1350 AD
This collar is very rare, and shows extremely skilled craftsmanship. It is made of hundreds of tiny circles of metal linked together, called mail. At the time this collar was made soldiers wore full suits of armour made of solid plates of metal. Mail was still worn underneath this, especially in the weaker places where the plates joined. A helmet would protect the knight's head, but there was nothing to cover their neck and shoulders, so it was particularly important to wear a mail collar.
The collar is made mostly of iron, which would have looked black. It is decorated with gold-coloured copper links, so it would have looked very smart.