The maesters are a fictional order of scholars and healers/physicians in George R. R. Martin's A Song of Ice and Fire. They are also scientists, advisors to the nobility, and occasionally pseudo-religious researchers in the occult. Males of any age may begin training as a maester; females are not permitted to study or join the order. Noble families in Westeros sometimes send their younger sons to the Citadel. The maesters, like the brothers of the Night's Watch, are considered to be servants of Westeros and all its people and in theory have no political allegiance. After finishing his course of study, a maester is assigned to a castle, keep or other holding, and is loyal to the people of that place as a mentor, healer and advisor, regardless of changes in control of that holding. To this end a man who earns his chain is stripped of his family name and from that time on is known only by his title and first name. In practice some maesters hold over old allegiances and loyalties.