A schoolmaster, or simply master, is a male school teacher. The usage first occurred in England in the Late Middle Ages and early modern period. At that time, most schools were one-room or two-room schools and had only one or two such teachers, a second or third being often called an assistant schoolmaster. The use of the traditional term survives in British private schools, both secondary and preparatory, and in grammar schools, as well as in some Commonwealth boarding schools (such as the Doon School in India) which are modelled on British grammar and public schools. Source: Wikipedia (en)