The first group of people to bake bread were ancient Egyptians, in 8000 BC.
During the Middle ages, it was common for each landlord to have a bakery, which was actually a public oven; Housewives would bring dough that they had prepared to the baker, who would use the oven to bake it into bread. As time went on, bakers would also bake their own goods. Some bakers would have trap doors, that would allow a small boy to pinch off a bit of the dough, where he could sell it off as his own. This practice eventually lead to the famous regulation known as 'Assize of Bread and Ale, which provided harsh punishments toward bakers who were found cheating. In response, bakers commonly threw in one more loaf of bread; this tradition now exists in the phrase "baker's dozen", which is number 13.-From Wikipedia.
I wonder what the Egyptian ovens looked like?
And in the Middle Ages--an oven with a trap door? How cool!