The earliest date from which neck watches (or pendant watches) can be traced at present is 1545. The exact date of the transition from 'high' drum watches to flat neck watches is uncertain.
The movements usually have 'Stackfreed' to compensate unequal force of the mainspring - this allows for a flat design and avoid mainspring cases. The watch shown below has an engraved coat of arms on the reverse - which can be ascribed to the Nuremberg noble families of Pfinzing and Welser as well as Pfinzing's motto "Gott begnadet Hoffnung" (God graces hope).
Very early watches have all iron movements - from 1570 they are partly made of brass to reduce friction.