Companions -- 3 Caliphs -- 2 History 2 Muhammad, Prophet, d 632 -- 2 Caliphate -- 1 Caliphs 1 Educational leadership -- 1 Educational surveys -- 1 Government -- 1 Islam -- 1 Kurafat movement 1 Muhammad, Prophet, d. 632 -- 1 School management and organization -- 1 School principals -- 1 United States 1 United States -- 1