Pie type foods are common to many different countries, in several different forms. Putting food on a base of pastry (as in pizza)is so common it is not possible to give it an origin.

Pie has been around since the about 2000 B.C. during the time of the ancient Egyptians. Between 1400 B.C. and 600 B.C., it’s believed pie was passed on to the Greeks and then spread to Rome around 100 B.C. The early Romans’ pies were sometimes made in “reeds” which were used for the sole purpose of holding the filling and not for eating with the filling. The early pies were predominately meat pies. Pyes (pies) originally appeared in England as early as the twelfth century. The crust of the pie was referred to as “coffyn”. There was actually more crust than filling. Often these pies were made using fowl and the legs were left to hang over the side of the dish and used as handles. Fruit pies or tarts (pasties) where probably first made in the 1500s. English tradition credits making the first cherry pie to Queen Elizabeth I. Over the years, pie has evolved to become what it is today “the most traditional American dessert.” Pie has become so much a part of American culture throughout the years, that we now commonly use the term “as American as apple pie.” http://content.foxsearchlight.com/inside/node/1917

Pies have been around for thousands of years, but for the food item that we commonly think of as pie, it's been around only about 600 years from UK. The first pies, called "coffins" or "coffyns" were savory meat pies with the crusts or pastry being tall, straight-sided with sealed-on floors and lids. Open-crust pastry (not tops or lids) were known as "traps." These pies held assorted meats and sauce components and were baked more like a modern casserole with no pan (the crust itself was the pan, its pastry tough and inedible). The purpose of a pastry shell was mainly to serve as a storage container and serving vessel, and these are often too hard to actually eat. A small pie was known as a tartlet and a tart was a large, shallow open pie (this is still the definition in England). Since pastry was a staple ingredient in medieval menus, pastry making was taken for granted by the majority of early cookbooks, and recipes are not usually included. It wasn't until the 16th century that cookbooks with pastry ingredients began appearing. Historian believe this was because cookbooks started appearing for the general household and not just for professional cooks. 1545 - A cookbook from the mid 16th century that also includes some account of domestic life, cookery and feasts in Tudor days, called A Proper newe Booke of Cokerye, declarynge what maner of meates be beste in season, for al times in the yere, and how they ought to be dressed, and serued at the table, bothe for fleshe dayes, and fyshe dayes, has a recipe for a short paest for tarte: To Make Short Paest for Tarte - Take fyne floure and a cursey of fayre water and a dysche of swete butter and a lyttel saffron, and the yolckes of two egges and make it thynne and as tender as ye maye. Historians have recorded that the roots of pie can loosely be traced back to the ancient Egyptians. The bakers to the pharaohs incorporated nuts, honey, and fruits in bread dough, a primitive form of pastry. Drawings of this can be found etched on the tomb walls of Ramses II, located in the Valley of the Kings. King Ramses II was the third pharoh in the nineteenth dynasty. He ruled from 1304 to 1237 B.C. After years of the tombe being looted and weathered, great amounts of effort are in progress with the hope of returning the tomb to a somewhat presentable stage. Historians believe that the Greeks actually originated pie pastry. The pies during this period were made by a flour-water paste wrapped around meat; this served to cook the meat and seal in the juices. The Romans, sampling the delicacy, carried home recipes for making it (a prize of victory when they conquered Greece). The wealthy and educated Romans used various types of meat in every course of the meal, including the dessert course (secundae mensea). According to historical records, oysters, mussels, lampreys, and other meats and fish were normal in Roman puddings. It is thought that the puddings were a lot like pies.. The Roman statesman, Marcus Porcius Cato (234-149 B.C.), also know as Cato the Elder, wrote a treatise on agriculture called De Agricultura. He loved delicacies and recorded a recipe for his era's most popular pie/cake called Placenta. They were also called libum by the Romans, and were primarily used as an offering to their gods. Placenta was more like a cheesecake, baked on a pastry base, or sometimes inside a pastry case. The delights of the pie spread throughout Europe, via the Roman roads, where every country adapted the recipes to their customs and foods. Bake Metes and Mince Pies, Historic Foods, by Ivan Day, 2003 http://whatscookingamerica.net/History/PieHistory.htm