As a boy of 15, Blomefield began recording monumental inscriptions from churches he visited in Norfolk, Suffolk and later Cambridgeshire. Whilst at college, he also kept genealogical and heraldic notes relating to local families. Soon after leaving university, he was collecting materials for an account of the antiquities of Cambridgeshire, but in 1732, this project was deferred when he was given access to the antiquary Peter Le Neve's collection of materials for the history of Norfolk by Le Neve's executor "Honest Tom" Martin.