Bread wheat was the accidental " unnatural " crossing of einkorn and then emmer wheat with another species.
Originally grown as far back as 5,000 BCE, the only grains known to be cultivated before spelt are elkorn and emmer.
The Emmer, also belonging to the Weser system, is its chief stream.
The principal tributaries on the right are the Aller, Wi mme, Drepte, Lune and Geeste, and on the left the Diemel, Nethe, Emmer, Werra, Aue and Hunte.