The High School, or Gordonville Ladies' Academy as it was originally known, was founded in 1875 in Alexander Terrace, Coleraine, by Mrs Long, assisted by her daughter and staff.
In 1959, the day school was transferred to the County Londonderry Education Committee, and then, in the local government re-organisation of 1973, to the North Eastern Education and Library Board as a controlled grammar school.
The school moved from the "Gordonville" site in 1966 when the present buildings were completed and a further extension was added in 1971.
The school is divided into four houses: As of February 2012, the old boarders building of Spring Gardens has been demolished.
The new school is currently on both the CHS and CAI campuses and started accepting pupils in September 2015.