The first 10 girls admitted to the school arrived on 28 February 1948 and came from the all the different provinces in Kenya as is still the case today. In 1961, Alliance Girls High School was one of the first five schools in Africa to offer the Higher School Certificate (at the time, the equivalent of A Levels and a requirement for university entrance).[3] Prior to the establishment of Alliance Girls High School, a few girls had been admitted to the predominantly male Alliance High School. One of the last girls to graduate from there was the writer Rebeka Njau who later taught at the Alliance Girls High School.[4][5] The two schools continue to maintain close relations.