The local area has been worked for iron ore since Roman times. An ironstone industry developed in the 19th century with the coming of the railways and the discovery of extensive ironstone beds. By 1910 an ironstone works had been established. In 1931 Corby was a small village with a population of around 1,500.
The village grew rapidly into a reasonably sized industrial town, when the owners of the ironstone works, the steel firm Stewarts & Lloyds, decided to build a large integrated ironstone and steel works on the site. The start of construction in 1934 drew workers from all over the country including many workers from the depressed west of Scotland and Irish labourers.
The first steel was produced in October 1935 and for decades afterwards the steel works dominated the town. By 1939 the population had grown to around 12,000, at which time Corby was thought to be the largest "village" in the country, but it was at that point that Corby was re-designated an urban district