Diocesan Girls' School, one of the oldest girls' schools in Hong Kong, was founded in 1860 by the Anglican (Episcopalian) Church to provide an all-round secondary education for girls in Hong Kong. Commonly known as DGS, the School is governed by the Council of the Diocesan Girls' School, a group of administrators who ensure that the school is well-managed and adheres to DGS's School Mission. Having run as a grant-aided school since it was founded, the School commenced operation in the DSS mode starting with Secondary One classes in September 2005. It uses English as the medium of instruction, and has always been ranked as one of the top secondary schools in Hong Kong, with students known to be high achievers in academics, music and sports etc. DGS counts a total of 43 winners of the Hong Kong Outstanding Students Awards, ranking first among all the secondary schools in Hong Kong, and outnumbering the combined number of winners of the next two schools. The school is also a member of the G20 Schools group.