[2][3] In 1537, Thomas Howell, a Welsh merchant trading in Bristol, London and Seville, bequeathed 12,000 gold ducats to the Drapers' Company to provide dowries "every yere for Maydens for ever.

It was originally housed in a building designed by Decimus Burton, on the outskirts of the village of Llandaff.

Novelist Roald Dahl spent part of his childhood at Cumberland Lodge, which was later acquired by the school.

[7] In 2005 The school opened the GDST's first co-educational sixth form with the admission of 26 boys into year 12.

[3][9] In 2011 it made the top 100 schools in the United Kingdom based on GCSE results and ranked first in Wales.