The creator of the first watch portable time piece was named Peter Henlein who lived from 1485-1542. He was a locksmith and clockmaker from Nuremberg, Germany. He is often considered the inventor of the first watch.
He originally crafted a small ornamental taschenuhr. These were small portable clocks that were worn around the neck as pendant or sometimes just attached to clothing. These were regarded as the first ‘watches’. There are quite a few sources that also credit Peter Henlein for the created of the mainspring.
Above is a picture of Peter Henlein.
To learn much more about Peter Henlein’s life you can head over to his wiki page.