 It has been rated as Excellent for current performance and Excellent for prospects for improvement by Estyn (2013) the school achieved its highest ever results in 2016 with 92% of students achieving Level 2+ (5 GCSEs including English and Mathematics) and a 100% achieving at least 5 GCSEs.Although the school was established in its current form in 1970, its origins go back much further to the foundations of the three schools that merged to form the present school.City of Cardiff High School for Girls was opened in January 1895 in the Parade, Cardiff, with Mary Collin as its first headmistress, and City of Cardiff High School for Boys was opened in September 1898 in Newport Road, Cardiff.