The term "feu" (French for "fire" from the Latin focus meaning hearth) meant, especially in the Middle Ages, the hearth, first in the strict sense (the place where the fire burns) and figuratively: the family home (cf. the expression "without fire or place"[1]) or the family itself. Very quickly, it was used as the basic unit for assessment, calculation, and collection of tax and it was called the "feu fiscal" meaning "fire tax".