Before watches, there were clocks. Before clocks, there was simply mechanism to tell and measure time. Sundials told time by shadows. Hourglasses measured time by predictable rates of sand moving through a narrow channel.
Some would say that early Egyptians were the first to create a mechanical way of measuring time by the flow of running water. The earliest accurate clocks were built by monks in Italy to simply tell you what time to pray. Theses clocks told time audibly with bells and had no hand indicators.
In the 16th century pocket watches were invented in Tudor, England. The watches were incredibly big and were generally worn around the neck because of their girth. It is rumored that in the famous painting of Henry VIII, it was not a medallion around his neck, but a pocket watch he owned. While pocket watches were invented in the 16th century, it was not until the 17th century that they became more common and accurate.
In the 1700’s, Queen Anne of England wanted to extend her vast maritime power and offered a huge reward of 20,000 pounds for anyone who invented something that reliably calculated longitude.
A self-taught watchmaker by the name of John Harrison discovered that a precise reading of a ships longitude could only happen if you knew the exact time. At this point, Harrison decided that he needed to create a watch that was far more accurate then what was available at that time. He worked for more then ten years to create 4 versions of the Harrison Marine Chronometer. He presented his plate sized watch to the royal academy and had his chronometers tested by people like Captain Cook. Harrison’s Marine Chronometer went through many trials and eventually was accepted by the Queen who then paid him his prize money of 20,000 pound.
It took until the 19th century for the wristwatch technology to come to fruition. The wristwatch was invented by Patek Philippe. From the time of its invention until world war one, the wristwatch was mainly considered something that a woman would wear. Men, to that point had generally used pocket watches. In the midst of war, some armies soon realized that it was much easier to glance at your wrist to check the time, than it was to fumble around in your jacket to find your pocket watch. When the war ended, the soldiers got to keep their army issued wristwatches. They must have gotten used to wearing a wristwatch everyday, because soon after the war ended, it became common to see civilian men wearing wristwatches in public. Some might argue that World War 1 was the one single event that spurred the entire wristwatch industry, and I guess the rest, is what we call history.