Before the Europeans came across the pond to explore and exploit the Western Hemisphere, there was no knowledge of corn in Europe. Corn was a crop indigenous to north and south America, like potatoes, tomatoes and chocolate. After the exploration and colonization of the New World, these crops were taken to the old world and began to be grown there. We are all familiar with potatoes growing in Ireland, and tomatoes in Italy (by the way, whatever did Sicilians use on their spaghetti before tomatoes?).
In Europe, corn was used as corn on the cob, and as ground meal for cornbread and polenta. But there was a problem. People who ate a diet high in corn often developed Pellagra, a disease of niacin deficiency, and worse, many died of a poison in spoiled corn called aflatoxin. The Indians of the Americas had discovered that by treating corn with a strong alkaline solution it both softened the corn, and made the niacin bio-available (though I doubt they knew the chemistry). In addition, this process killed the poisonous aflatoxin. In Mexico this treated corn is called Nixtamal. It is used to make Pozole (Puh-SOL-ee) and ground into flour it is used as the basis for corn tortillas. Nixtamalization made the corn safe and nutritious. We have no idea how the ancient ones discovered this, but they had millennia to do it. In north America this treated corn is called Hominy, and when dried, ground, and boiled in water it is known as “grits”, a staple of Southern cooking and a favorite of some chuck wagon cooks.