The popular history behind French toast (aka German toast, American toast, Spanish toast) is that it was was created by medieval European cooks who needed to use every bit of food they could find to feed their families. They knew old, stale bread (French term *pain perdu* literally means *lost bread*) could be revived when moistened and heated. Cooks would have added eggs for additional moisture and protein. Medieval recipes for "french toast" also suggest this meal was enjoyed by the wealthy. Cook books at this time were written by and for the wealthy. These recipes used white bread (the very finest, most expensive bread available at the time) with the crusts cut off, something a poor, hungry person would be unlikely to do.
Actually, recipes for "french toast" can be traced Ancient Roman times. One of the original French names for this dish is pain a la Romaine', or Roman bread. Apicius wrote: "Another sweet dish: Break [slice] fine white bread, crust removed, into rather large pieces which soak in milk [and beaten eggs] Fry in oil, cover with honey and serve." ---Apicius Cookery and Dining in Imperial Rome, edited and translated by Joseph Dommers Vehling , recipe 296 (p. 172)
"This dish does have its origins in France, where it is known as "ameritte" or *pain perdu* ("lost bread"), a term that has persisted, in Creole and Cajun cookery; in Spain it is called "torriga" and in England "Poor Knights of Windsor," which is the same name for the dish in Denmark, "arme riddere," and Germany, "arme ritter." At one time or another in America it has been referred to as "Spanish," "German," or "nun's toast," and its first appearance in print as "French Toast" was in 1871. "
---The Encyclopedia of American Food and Drink, John F. Mariani (p. 134)
"In the south of France, it was traditionally eaten on feast days, particularly at Easter."
---Larousse Gastronomique, Jenifer Harvey Lang (p. 474)
"French toast is a dish we have borrowed from the French, who call it pain perdu', or lost bread...It is known in England as the poor knights of Windsor, which is the same phrase used in many countries: fattiga riddare' in Sweden; 'arme ridder' in Danish; and armer ritter' in German. One theory about how the latter name came about goes as follows: In olden times, one of the symbols of distinction between the gentry and the common herd was that the former were expected to serve dessert at dinner. Knights, of course, were gentry. But not all of them were rich. Those who were not, in order to maintain their status, made do with armer ritter', often served with jam."
---Craig Claiborne's The New York Times Food Encyclopedia, Craig Claiborne (p. 178)
Interested in old recipes?
"Suppe dorate [Gilded sippets]
Take slices of white bread, trimmed so that they have no crusts; make these slices square and slightly grilled so that they are colored all over by the fire. Then take eggs beaten together with plenty of sugar and a little rose water; and put the slices of bread in this to soak; carefully remove them, and fry them a little in a frying pan with a little butter and lard, turning them very frequently so that they do not burn. The arrange them on a plate, and top with a little rose water colored yellow with a little saffron, and with plenty of sugar."
---The Medieval Kitchen, Recipes from France and Italy, Odilie Redon et al, (p.207)
(recipe translated from Libro de arte coquinaria, Maestro Martino )
To one egg thoroughly beaten, put one cup of sweet milk, and a little salt. Slice light bread and dip into the mixture, allowing each slice to absorb some of the milk; then brown on a hot, buttered griddle or thick-bottom frying pan; spread with butter, and serve hot."
---White House Cook Book, Mrs. F. L. Gilette  (p. 246)
"French Toast (Amarilla)
4 slices sandwich bread
1/3 cup milk
Sugar and cinnamon mixture
Cut bread as for toast, without removing crust. Beat egg slightly, add milk. Dip bread slices with a fork into milk mixture, moistening well on both sides, not too wet. Cover bottom of a hot skillet one inch or more with hot or rendered butter. Brown moistened bread quickly as soon as dipped, first on one side then on the other in hot butter. Do not cook more than two or three slices at one time. If cooked too slowly, toast will be greasy. Drain and sprinkle while hot with confectioner's sugar and cinnamon mixed together."
---Every Woman's Cook Book, Mrs. Chas. F. Moritz  (p. 509)