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.
“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
“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