Way back in the 3rd century AD, the innovative Romans began producing door locks made entirely of metal. Before that, all locks were completely or partially made of hard wood materials, although the keys could be made of bronze or iron. Wooden locks were used in large parts of Europe all the way into the 2oth century. There are three main types of wooden locks:
- Pin tumbler locks, including peg tumbler locks, Egyptian, Spartan and Celtic locks.
- Sliding bolt locks.
- Wooden block locks (with turning key).