The exact origins of pretzels are unknown, but most sources cite 7th century monks in Italy or Southern Germany who adapted the Greek ring bread, which is itself derived from communion bread. The monks were said to have baked treats made of dough folded to resemble a person’s arms crossed in prayer. These “pretiolas”, or little treats, were given to children. By the 12th century, pretzels, or bretzels, were firmly established in the German baking tradition, to the extent that the pretzel was used for the first time as the symbol of the German Baking Guild. It remains the emblem of many baking guilds today.
The first visual record of the pretzel is a frame from the illustrated manuscript Hortus Deliciarum, a 12th century work from Alsace (then part of Germany). The picture is a a scene from the Megillah, the Hebrew text describing the story of the holiday of Purim. Queen Esther and her evil husband King Ahasuerus are shown with a pretzel on a banquet table. More can be read about the story of Purim here: http://www.jewfaq.org/holiday9.htm
Pretzels were eaten traditionally as Lenten bread; they contain no dairy, and as such are suitable to be eaten between Ash Wednesday and Easter. The three holes of the pretzel are said to symbolize the Holy Trinity. Pretzels spread around Europe along with their traditions. Pretzels today signify the Catholicism of Southern Germany, making them a unique bread tied to religion and culture.
Legend has it that a baker, neglectful while baking pretzels, left them in the oven a bit too long, until they were dried out and hard. He realized that these pretzels were still delicious and had the advantage of keeping for longer. From then on, hard pretzels were given as charity to the poor.
Making pretzels is quite simple, but has a bit of added danger (which I think makes them rather exciting to make): it is best to dip the raw dough into a dilute lye solution. Lye, a powerful industrial cleaner, is a strong alkaline, which has a PH of 13. This helps promote the Maillard reaction when the pretzels are baked, giving them a deep mahogany gloss. If you do not wish to use lye, you can also use a baking soda solution. I use the recipe from Smitten Kitchen here: http://smittenkitchen.com/blog/2014/05/soft-pretzel-buns-and-knots/
And here they are!