The new school opened and was granted a Royal Charter in 1562. By the letters patent of 1555, the school was called in full 'The Free Grammar School of Sir John Gresham, knight, citizen and alderman of London'. The founder endowed Gresham's generously, placing its property in trust with the Worshipful Company of Fishmongers of London, and full estate records dating from the school's foundation are held at the Guildhall Library. Sir John Gresham's endowments included his freehold property in Holt and Letheringsett, his wood and land called Prior's Grove, his manors of Pereers and Holt Hales, "with all and singular to the same belonging, situate in Holt, Sherington, Letheringsett, Bodham, Kellinge, Wayborne, Semlingham, Stodrye, Bantrye and West Wickham, in the said county of Norfolk", and also tenements called 'The White Hind' and 'The Peacock' in the parish of St Giles's Without, Cripplegate, in the City of London. Close links with the Fishmongers' Company continue to this day.