The courts of the king and barons became schools of chivalry wherein seven year old noble boys became pages or valets, wore a dagger and waited upon the ladies of the household. At age fourteen, they were advanced to squires and admitted into more familiar association with the knights and ladies of the court. They perfected their skills in dancing, riding, fencing, hawking, hunting, jousting, and engaged in team sports in which the goal was to put the other side to rout. They learned the knightly art of war. Enemy fighters were to be taken and held for ransom rather than killed. Those engaging in rebellion were to be pardoned and restored to some or all of their lands and titles. Lords' sons could be mutually exchanged with an enemy's as security for peace. After achieving knighthood, a man usually selected a wife from the court at which he grew up. Parents tried to send their daughters to a household superior in social status not only to learn manners, but to make a good marriage. A girl who did not marry was often sent to a nunnery; a dowry was necessary before her acceptance. The following incidents of land tenure began (but were not firmly established until the reign of Henry II). Each tenant, whether baron or subtenant, was to pay an "aid" in money for ransom if his lord was captured in war, for the knighthood of his lord's eldest son, and for the marriage of his lord's eldest daughter. The aid was theoretically voluntary. Land could be held by an heir only if he could fight. The eldest son began to succeed to the whole of the lands in all military tenures. Younger sons of great houses became bishops. An heir of a tenant had to pay a heavy "relief" on succession to his estate. The relief replaced the heriot. If there was a delay in proving heirship or paying relief, the lord would hold the land and receive its income in the meantime, often a year. If an heir was still a minor or female, he or she passed into his lord's wardship, in which the lord had guardianship of the heir and possession of the estate, with all its profits. The mother was not made a minor's guardian. No longer was the estate protected by the minor's kin as his birthright. A female heir was expected to marry a man acceptable to the lord. The estate of an heiress and her land was generally sold to the highest bidder. If there were no heirs, the land escheated to the lord. If a tenant committed felony, his land escheated to his lord. The word "felony" came from the Latin word meaning "to deceive" and referred to the feudal crime of betraying or committing treachery against one's lord. Astrologers resided with the families of the barons. People went to fortune tellers' shops. There was horse racing, steeple races, and chess for recreation. Girls had dolls; boys had toy soldiers, spinning tops, toy horses, ships, and wooden models. The state of medicine is indicated by this medical advice brought to the nation by William's son after treatment on the continent: