Surviving in a limited form after the fall of the Roman empire, until the 12th century the use of iron was restricted to weapons,
mail hauberks, and
casques or spangen helmets. During the 13th century sources for iron became more plentiful, and during the 14th century it became commonly available for use by armourers. Recent tests by the Swiss Institute for Arms and Armour have shown that during the 15th century the use of
steel , iron strengthened by the addition of carbon, was mastered by both Italian and German craftsmen. After the middle of the century most armour was made from steel rather than iron, making it more durable, resistant to
rust , and more easily heat-treatable.
