French toast is a dish of bread soaked in eggs then fried.
When French toast is served as a sweet dish, milk, sugar, or cinnamon are also commonly added before frying, and then it may be topped with sugar, butter, fruit, syrup, or other items. When it is a savory dish, it is generally fried with a pinch of salt, and can then served with a sauce.
The earliest known reference to French toast is in the Apicius, a collection of Latin recipes dating to the 4th or 5th century; the recipe mentions soaking in milk but not eggs (though the editor adds eggs) and gives it no special name, just Aliter Dulcia 'another sweet dish'. There is a 14th-century German recipe under the name "Armeritter". There are 15th-century English recipes for "pain perdu" (French for "lost [or wasted] bread", suggesting that the dish is a use for bread which has gone stale).
A 1660 recipe for "French Toasts" is different: toasted bread is soaked in wine, sugar, and orange juice.
A similar dish, suppe dorate, was popular in England during the Middle Ages, although the English might have learned it from the Normans, who had a dish called tostees dorees.