Ever wondered where the term 'Baker's Dozen' comes from?
It is said to date back to 13th century England, when King Henry III introduced one of the earliest English statutes: the Assize of Bread and Ale. It basically said that there would be sever punishments for any Bakers found to be selling underweight or inferior bread. Punishments included having one's hand chopped off with an axe.
So bakers began making 13 loaves for every 12 ordered to ensure they always had one more in case of burnt, lost or small loaves.