it is believed that Pie pastry was originated in ancient Greece and Rome, dough made with olive oil were used to cover or enclose various ingredients.
In English, the word pie used in this way dates to at least 1300. It is probably a short form of a magpie, a bird that collects a variety of things, just as bakers do when they are assembling ingredients to bake in a pie.
North Americans are responsible for turning the development of pies firmly away from savory and toward sweet. Fruit pies, especially apple, are perhaps still the most popular but, but pastry cooks have devised dessert pie fillings from many other ingredients as well.