Sandwich, in its basic form, can be defined as slices of meat, cheese, or other food placed between two slices of bread.

According to whatscookingamerica.net however, the first recorded sandwich was by the famous rabbi, Hillel the Elder, who lived during the 1st century B.C.  He started the Passover custom of sandwiching a mixture of chopped nuts, apples, spices, and wine between two matzos (unleavened flatbread that is part of Jewish cuisine and forms an integral element of the Passover festival). The filling between the matzos served as a reminder of the suffering of the Jews before their deliverance from Egypt and represented the mortar used by the Jews in their forced labour of constructing Egyptian buildings.

During the Middle Ages, thick blocks of coarse stale bread called trenchers were used in place of plates.  Meats and other foods were piled on top of the bread to be eaten with their fingers and sometimes with the aid of knives.  The trenchers, thick and stale, absorbed the juice, the grease, and the sauces.  At the end of the meal, one either ate the trencher or, if hunger had been satisfied, tossed the gravy-soaked bread to their dogs or given as alms to less fortunate humans.

Although this mode of consumption must be as old as meat and bread, the name was adopted only in the 18th Century for John Montagu, 4th earl of Sandwich. This is according to Britannica.com.

According to an often-cited account from a contemporary French travel book, Sandwich had sliced meat and bread brought to him at the gaming table on one occasion so that he could continue to play as he ate; it seems more likely, however, that he ate these sandwiches as he worked at his desk or that the world became aware of them when he requested them in London society.

John Montagu’s biographer, N. A. M. Rodger, points out in the book, The Insatiable Earl – A Life of John Montagu, 4th Earl of Sandwich, that the sole source for giving Montagu credit for the invention of the sandwich, was gossip mentioned in a travel book by Grosley, and that at the period in question 1765, he was known to be very busy, and it is just as likely that it was for the purpose of eating at his desk.

His title lent the preparation cachet, and soon it was fashionable to serve sandwiches on the European continent, and the word was incorporated into the French language. Since that time the sandwich has been incorporated into virtually every cuisine of the West and adopted worldwide, by virtue of its simplicity of preparation, portability, and endless variety.