Short answers, pulled from the story.
A crank is an arm attached at a right angle to a rotating shaft that imparts circular motion. When combined with a connecting rod, the mechanism converts circular motion into reciprocating motion or vice versa.
Evidence of the earliest true crank handle appeared during the Han era no later than 200 AD. One specific model dates back to the Western Han dynasty which spanned from 202 BC to 9 AD.
The Hierapolis sawmill operated in Roman Asia during the 3rd century AD. This machine utilized a crank combined with a connecting rod to power stone saws.
Guido da Vigevano lived from 1280 to 1349 and planned illustrations for paddle boats propelled by manually turned compound cranks. His war carriages featured gear wheels alongside these cranks.
The Citroën 2CV produced between 1948 and 1990 was the last car model incorporating a crank. A 1918 Reo owner manual details how operators had to hand crank an automobile engine before electric starters became common.