During the Middle Ages "hidalgo" became a title granted by the kings of Castile as a reward for service done to the crown (or, as in Biscay, as a way of recognizing prior rights). In the same way "escudero" was granted for military achievement when the "Reconquista" ended. Being the most obvious proof of noble descent, "hidalgo" came to be the only lesser title to remain among the modern ranks of Spanish nobility. From this ancient estate of the realm emerged Spain's nobility. All titled and untitled nobles are considered "hidalgos", but many of the modern titled nobility do not descend from the original "hidalguía".