In a Riverford Farm newsletter back in August this year Guy Singh-Watson wrote about his memories of harvest that was done with a tractor-drawn binder. The cereals were then threshed in a standalone machine to separate the grain from the straw and chaff. These days that work is done with a combine harvester.
Guy linked to a fantastic 1943 film called Stooking and Stacking which shows some of the harvesting process.