In the Game of Thrones universe, Maesters are important figures in society who devote their lives to studying and attending to noble houses’ needs. They’re responsible for the children’s education and every medical matter at the castle, from childbirth to using medicinal herbs and much more. In addition, they serve as advisors to the Lord or Lady in charge and the Grand Maester is usually a part of the Small Council.
Source：https://www.cbr.com/game-of-thrones-maesters-importance-ranked/
