Harrow School, often called simply "Harrow", is a secondary school for boys in Harrow in London, England. Harrow has educated boys since 1243 but was officially founded by John Lyon under a Royal Charter of Elizabeth I in 1572. Harrow is located in Harrow on the Hill, now in the London Borough of Harrow. The school has about 800 students. They live across twelve boarding houses, and all of them board full time.