The origins of the pretzel go back to a frugal monestery in the mountains between Southern France and Northern Italy. In 610 AD the monks created the first soft pretzels. They didn't want to waste the dough leftover from making unleavened communion bread.

Christians in those days prayed with their arms crossed over their chest, with each hand on the opposite sholder. The monks realized that the dough could twisted into a similar shape. The treats were given to village children as a reward to children for memorizing their prayers.

The monks called their treats Pretiols, a Latin word that means "Little reward". As time passed Pretiols became known as Brachiola, an Italian word meaning "little arms." The popular Brachiola eventually crossed the Alps into Austria and Germany, where it became even more popular. There it became known as the Bretzel.

Pretzels quickly became a popular pre-Easter food throughout the Middle Ages. During the Lenten season Christians were forbidden to prepare food that contained eggs, milk, butter & lard, none of these were ingredients in early pretzels.

The earliest depictions of the pretzel come to us from a 1440 prayer book portraying St. Bartholomew - surrounded by pretzels. By that time, the pretzel had come to symbolize good luck, prosperity and spiritual wholeness. Children in German still wear pretzels around their neck on New Year's.

In 1510, the city of Vienna was under attack by the Turks. During the night, the Turks tried to dig a tunnel under the city walls. Some busy pretzel bakers heard them digging and scraping. They alerted the Viennese public who banded together, charging the Turks in the tunnels and won the battle. As a sign of his gratitude, the king bestowed on the Viennese pretzel bakers a special coat of arms. The shield was decorated with a charging lion and a pretzel. This became the baker's emblem still in use today.

By the 1600s, pretzels had became a convenient way to give food to the poor, a typical alms for the hungry. Coffins were also packed with pretzels as a burial blessing.

A woodcut from 1614, copied from a Switzerland cathedral window, depicts the "marriage knot" as a pretzel. The new couple would make a wish and break the pretzel like a wishbone, then ate it to signify their oneness. This is a possible origin of the phrase "tying the knot."

The medieval pretzel may not have been the salted treat we know and love it today. The sugar or chocolate-coated types were popular with the medieval peoples, as evidenced by a 16th century recipe, translated below:

Take white flour, only the white of eggs and some wine, sugar and anise, prepare a dough with these ingredients, roll the dough with clean hands such that it becomes longish and round. Make small pretzels from it and put them into a warm oven and bake them so that you do not burn it but that they are well dried. This way, they will become crisp and good. If you like, you may take cinnamon as an ingredient for the dough, too (but you can leave it). This dish is called Precedella.

From these humble beginnings, the pretzel has become a popular treat. It is possibly one of the world's most popular ancient junk foods.

References:

Tracy Brant's Pretzel Timeline

Traditional Holiday Pretzel Crafts

Snyders of Hanover's Pretzel History

Medieval Inventions: The Pretzel