 In his will dated 8 July 1557, he left the property and endowments towards establishing the school.The will had left the property to his brother William Glyn, Bishop of Bangor and Maurice Griffith, Bishop of Rochester to execute his wishes.Unfortunately both of these were to die in the following year, but they further transferred the will to Sir William Petre, a former Secretary of State, Sir William Garrard, a former Lord Mayor of London and Simon Lowe, a London merchant tailor, who were able to execute Geoffrey Glyn's intentions.