 Prior to becoming Queen Elizabeth Cambria and Queen Elizabeth Maridunum Schools, they were Ystrad Tywi school, (a Secondary Modern School which had merged with Queen Elizabeth Grammar School in 1978) and a Girls Grammar School respectively.In September 2005 the two schools merged to form Queen Elizabeth High School as part of the Modernising Education Programme by Carmarthenshire County Council.In 2006 all key stage 3 students were based on the Maridunum, or lower, campus and all GCSE and A-Level students were based on the Cambria, or upper, campus.