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Feb 9, 1571
Wristwatch
Elizabeth I of England received a wristwatch from Robert Dudley in 1571, described as an arm watch. -
Balance spring
More accurate timing -
Pocketwatches
Styles changed in the 17th century and men began to wear watches in pockets instead of as pendants (the woman's watch remained a pendant into the 20th century). -
Temperature compensation and chronometers
It was found that a major cause of error in balance wheel timepieces was changes in elasticity of the balance spring with temperature changes. This problem was solved by the bimetallic temperature compensated balance wheel invented in 1765 by Pierre Le Roy and improved by Thomas Earnshaw -
Lever escapement
Makes the watch more accurate -
Electronic movements
In 1959 Seiko placed an order with Epson (a daughter company of Seiko and the 'brain' behind the quartz revolution) to start developing a quartz wristwatch. The project was codenamed 59A. By the 1964 Tokyo Summer Olympics, Seiko had a working prototype of a portable quartz watch which was used as the time measurements throughout the event.