The name is a corruption of villa de Iseldon Berners (1274), being so called after the Berners family: powerful medieval manorial lords who gained ownership of a large part of Islington after the Norman Conquest. The area of Barnsbury was predominantly rural until the early nineteenth century.
By the end of the 18th century, however, Barnsbury, like other parts of Islington, was being regarded as attractive part-rural suburbs by the comparatively wealthy people wanting to move out of the cramped City of London and industrial Clerkenwell. The area is close to the City, and had strong local trade in its position as the first staging post for travellers making the journey from London to the north, and with considerable agricultural traffic and cattle driving to the nearby Smithfield cattle market in the City.
Pentonville Prison (built 1842) is located within Barnsbury.