It was a constituency of the House of Commons of the Parliament of the United Kingdom.

1885–1918: The Sessional Division of Smalley, and the parishes of Breaston, Draycott and Wilne, Hopwell, Longeaton, Ockbrook, Risley, and Sawley and Wilsthorpe in the Sessional Division of Derby.

[2] 1918–1950: The Municipal Borough of Ilkeston, the Urban Districts of Heanor and Ripley, and the Rural District which consisted of the parishes of Codnor Park and Shipley.

[3] 1950–1983: The Municipal Borough of Ilkeston, the Urban Districts of Alfreton, Heanor, and Ripley, and in the Rural District of Belper the parish of Shipley.

The political parties had been making preparations for an election to take place from 1939 and by the end of this year, the following candidates had been selected; Leigh Rayment's Historical List of MPs – Constituencies beginning with "I"