The first known restaurants in history were the thermopolia (singular thermopolium) of Ancient Greece and Ancient Rome, which literally meant “a place where something hot is sold”. These diner-bars consisted of a small room with a distinctive L-shaped counter in the front. Embedded in this counter were earthenware jars (called dolia) used to store food that could be eaten quickly or on-the-go. Fancier venues often included decorative frescoes or ornaments.
Here are some photos for reference (sorry for the poor quality in the first one):
These establishments were popular due to the lack of kitchens in most homes; in fact, unlike nowadays, eating out regularly was seen as an activity of the lower classes, since the wealthy could afford private kitchens. But like today, thermopolia were considered very important aspect of socializing and leisure. Well-preserved ruins of thermopolia can be seen in Pompeii and Herculaneum, the cities famously preserved by the eruption of Mount Vesuvius. In the former alone, 158 thermopolia have been identified, located mostly along the main axis of the town and the public spaces.
China saw the emergence of more sophisticated eateries, including the first known food caterers, in the 11th century, centered mostly around Kaifeng, the first capital of the Song Dynasty (960–1279). These likely grew out of the tea houses and taverns that catered to travelers (as in Europe, most places to eat and drink outside the home were exclusively inns and lodges). These restaurants blossomed into an industry in their own right, offering menus, different styles of cuisine, price brackets, and religious requirements. One interesting account from 1275 describes the restaurant business in terms that could apply today:
The people of Hangzhou are very difficult to please. Hundreds of orders are given on all sides: this person wants something hot, another something cold, a third something tepid, a fourth something chilled; one wants cooked food, another raw, another chooses roast, another grill.
The modern concept of a restaurant — as well as the term itself — originated in Paris, France in the late 18th century. The word comes from the French verb restaurer, meaning “to restore”, which reflected the fact that restaurants were originally founded for health reasons — namely to provide healthful foods and remedies. Below I’ll post some images of preserved thermpolia to give you a better picture (I sadly could find no account of historical Chinese restaurants).