Peter Henlein

Peter Henlein (or Henle or Hele) (1479/1480 – August 1542), was a locksmith and watchmaker from Nuremberg. He is often said to be the inventor of the watch. This is disputed. Henlein was certainly one of the first makers of the watch. Although many say that Henlein invented the mainspring, there are descriptions and two surviving examples show that spring driven clocks had already been made by the early 1400s. He did make improvements to the balance spring, which made it possible to make the watches smaller.
Around 1504 to 1508 Henlein did make a watch; a small, drum-shaped "Taschenuhr". It could run for forty hours before it needed rewinding. They were small enough to be worn around the neck, or carried in a bag or pocket. His watch only had an hour hand.