The early curriculum was based on Continental Calvinism, under its foundational headmaster, Thomas Ashton (appointed 1561) and boys were taught the catechism of Calvin. The school attracted large numbers of pupils from Protestant families in Shrewsbury, Shropshire and North Wales, with 266 boys on its roll at the end of 1562. Early pupils lodged with local families; Sir Philip Sidney (who had a well-known correspondence with his father about his schooling) lodged with George Leigh, Member of Parliament for Shrewsbury. Sidney attended the school along with his lifelong friend Fulke Greville (later Lord Brooke).