Founder of Trinity College, Oxford. -------------------- From 1556-1558, Sir Thomas was the guardian of Elizabeth Tudor, Queen Mary’s sister and heir, at Hatfield. At first, he entertained the princess with masques, pageants, and plays, but the queen put a stop to these amusements, calling them “follies.” By 1555, Sir Thomas had begun planning what was to become Trinity College, Oxford and after his death Elizabeth continued to be influential during the foundation’s early years.