The Exportation of Corn Act 1360 (34 Edward III c. 20) was an Act of the Parliament of England passed during the reign of Edward III.
The Act prohibited the exportation of corn to any foreign port except Calais and Gascony. If a corn harvest did not yield a lot of food, it was better for the corn to be used to feed the English rather than be exported.
References
Exportation of Corn Act 1360 Wikipedia(Text) CC BY-SA