There are two schools of thought on the history of tarts. One posits that tarts have evolved out of the “putting things on top of other things” tradition of gastronomy. According to this line of thought, human beings have been putting foodstuffs on top of other foodstuffs — notably round, flat pieces of bread — for millennia now. Since bread is made of flour and tart crusts are made of flour (albeit highly enriched flour), any of these foods counts as a tart. Technically. (People argue the same thing about cake…and pizza).
The second school of thought maintains that tarts spring from the Medieval pie-making tradition, and are in fact a kind of flat, open-faced pie. These folks have the shape and technique argument on their side, and I’m inclined to side with them. Enriched doughs (i.e. “short” crusts) came into common use about two hundred years after pies (about 1550 versus about 1350 or before for basic pie crusts), and in the same geographic area — Europe.
Pies and tarts differ in that while pie was a commoner’s sort of fare, a way of recycling offal and table scraps for later consumption (call it Medieval Tupperware), tarts were the stuff of high cuisine. Which is to say, they were extremely popular among the nobility. Court cooks employed tarts not so much for their taste but because of their looks. Often custard-based, a large, open tart presented a broad canvas upon which an artistic chef might compose a work of edible art. Thus brightly-colored fruits, vegetables and spices all found their way into (onto) them. They could be sweet, savory, or more often than not, a mixture of both.
Over time culinary trends took tarts primarily in the sweet direction (citrus tarts like orange and lemon are two all-time classics) though it’s important not to forget their famous savory cousins, quiches. I can’t say which of the two I prefer, though having already done quiche, I’ll concentrate on the sweet stuff this week.