Edward Underne became Rector of Chipping Barnet in 1568 and, along with other men of local influence actively promoted the establishment of a School in High Barnet.

When Elizabeth I granted the Charter for the founding of the School in 1573, Underne was given the task of raising the funds for the necessary buildings.

On the recommendation of the Canon of Windsor, the Corporation of London granted Underne permission to acquire funds for building the School from church collections within the City of London. Donations of churchgoers within the City of London financed the construction of the schoolhouse for 60-90 boys, incorporating a dwelling for the Master, dormitories in the roof space and turrets with staircases at either end.