The constituency was first created in 1832 as one of seven two-seat "metropolis" parliamentary boroughs (five in southeast Middlesex and two in northeast Surrey) other than the two which already existed: Westminster and the City of London; the latter until 1885 retained an exceptional four seats.
It included Finsbury, Holborn, Moorfields, Clerkenwell, Islington, Stoke Newington and historic St Pancras (later mainly known as Camden Town).
The commissioners appointed under the Boundaries Act decided to exclude the northern part of the Finsbury Division, which extended as far as Friern Barnet, some nine miles from London and a largely rural area.
They could find no natural boundary to separate "the Rural from the Town District" and suggested that the dividing line should run through the northern section of Islington, following limits of relatively recently founded Church of England parishes.
The political parties had been making preparations for an election to take place and by the Autumn of 1939, the following candidates had been selected;