Original: A vassal , in the terminology that preceded and accompanied the feudalism of medieval Europe , is one who enters into mutual obligations with a monarch , usually of military support and mutual protection , in exchange for certain guarantees , which came to include the terrain held as a fief .
Simplified: The development of the vassal , in a society that was increasingly organised around the concept of '' lordship '' -- in French the seigneur -- is one sign that Antiquity ended and the Early Middle Ages began .